refactor(planning): remove the original decision trace

CONTEXT.md

@@ -132,23 +132,8 @@ The numerical summary of a calculated valid plan's leave usage, time-off periods
 A stable account of why an optimization result or incomplete calculation contains its displayed leave placements, expressed through placement provenance, planning objectives, time-off periods, and remaining balances. It reports every contribution of a placement while highlighting the first planning objective that made its position decisive, and describes the displayed plan rather than the calculation history.
 _Avoid_: calculation explanation
 
-**Calculation trace**:
-The complete, untruncated, ordered history of the planning decisions and candidate evaluations from the same calculation that produced a planning outcome, grouped by calculation phase. It is not reconstructed by replaying the calculation afterward; for an incomplete calculation it ends at the actual interruption point.
-_Avoid_: plan explanation
-
-**Planning decision**:
-An atomic choice within a calculation phase that accepts, moves, removes, or rejects one or more related leave placements. A joint obligation decision may therefore concern several dates.
-_Avoid_: calendar day, step
-
-**Candidate evaluation**:
-The comparison the planner actually performs between a possible leave-placement change and the current plan. It belongs to the calculation trace whether the candidate is accepted or rejected.
-
-**Candidate date status**:
-The historical relationship between a date and a planning decision: chosen, evaluated and rejected, not examined, or ineligible with a reason. A later counterfactual date analysis never changes this historical status.
-
 **Counterfactual date analysis**:
-An on-demand evaluation that changes only the date of one selected leave placement while preserving its leave balance, leave type, and placement provenance. The planner did not necessarily examine that date; the analysis explains a hypothetical alternative but never influences the planning outcome and is not part of the calculation trace.
+An on-demand hypothetical comparison of another date for a displayed leave placement. It uses the immutable calculation configuration and final-state snapshot, preserving the same leave entitlement, leave type, and placement provenance while keeping unrelated placements fixed. It never mutates the displayed plan.
-_Avoid_: candidate evaluation, calculation trace
 
 **Conflict explanation**:
 A stable account of why no plan can jointly satisfy a set of obligation rules within the planning horizon and available leave balances.
@@ -166,12 +151,6 @@ The result of a calculation: invalid input, a planning conflict, an optimization
 **Stable plan explanation**:
 A deterministic explanation derived from the final displayed plan. It identifies each placement's entitlement and rule provenance, contributions, full objective vector, and the first objective that distinguishes the plan with that placement restored from the same plan with only that placement removed.
 
-**Original decision trace**:
-The untruncated phase-by-phase record captured by the calculation that produced the displayed outcome, including atomic decisions, candidate statuses, and state deltas. It is historical evidence and is never recomputed from the final plan.
-
-**Counterfactual date analysis**:
-A hypothetical comparison that keeps the calculation snapshot and all unrelated placements fixed while testing one selected placement across every date in the half-open planning horizon. It neither mutates the plan nor rewrites the original trace.
-
 **Incomplete calculation**:
 A calculation stopped by user cancellation or another interruption before it completed the planning objective order. On user cancellation it exposes its best available valid plan as partial, if one exists, and never implies that the obligations conflict.
 
@@ -192,4 +171,6 @@ A valid deterministic plan produced after completing the planning objective orde
 Any quantity left unspent by the optimization result, reported as unavoidable expiry, an unplaced at-risk balance, or a deferred balance.
 
 **Non-placement reason**:
-A concrete explanation of why a quantity of a leave balance remains unspent in the displayed plan, distinguishing a blocking condition from a decision to preserve leave for later. It includes the relevant dates, is distinct from the balance's expiry-based classification, and can be supported by recorded candidate evaluations.
+A concrete explanation of why a quantity of a leave balance remains unspent in the displayed plan, distinguishing a blocking condition from a decision to preserve leave for later. It includes the relevant dates, is distinct from the balance's expiry-based classification and is derived from the displayed plan.
+
+The original decision trace, historical date analysis, historical calendar replay, candidate statuses, and remaining-balance attempt lists were removed by issue #76. Calculations retain only the snapshots needed for outcomes, cancellation recovery, stable explanations, and displayed-placement date analysis.

README.md

@@ -11,7 +11,7 @@ The planner answers these questions:
 - What is the best plan found by the ordered heuristic?
 - If calculation stops early, what valid incumbent is available?
 - Why did each displayed placement survive the objective order?
-- Which alternatives were considered, and what would another date change?
+- What would another date change for a displayed placement?
 
 ## Architecture
 
@@ -37,25 +37,24 @@ flowchart LR
         Worker --> Core
         Core --> Holidays
         Worker -- "heartbeats, progress, checkpoints, outcome" --> Facade
-        Worker -- "after outcome: explanation + trace batches" --> Facade
+        Worker -- "after outcome: stable explanation + final state" --> Facade
-        Facade -- "trace acknowledgements" --> Worker
         Facade --> UI
     end
 ```
 
-Leave calculation stays in the browser. The production Express process serves the generated Angular application; it does not participate in planning. Browser calculations run cooperatively in a dedicated worker. The resumable core is emitted as a separate worker/lazy chunk and retains a synchronous adapter for direct core callers. Trace delivery uses bounded batches with receiver acknowledgements; large calendars and traces can still cause UI pauses and substantial memory use, as recorded in the benchmark report.
+Leave calculation stays in the browser. The production Express process serves the generated Angular application; it does not participate in planning. Browser calculations run cooperatively in a dedicated worker. The resumable core is emitted as a separate worker/lazy chunk and retains a synchronous adapter for direct core callers. The original decision trace and historical analysis were removed in issue #76; immutable checkpoints and final state remain available for cancellation recovery and displayed-placement alternatives.
 
 ### Main execution path
 
 1. `PlanningDurationService` reads the pending horizon, balances, and ordered rules to estimate the wait without running the planner.
 2. On startup or an explicit Calculate action, `CalendarYear` submits those inputs through `CalendarService`, which opens one immutable planning calculation context.
 3. `leave-planner.service.ts` copies the request into a canonical transport shape and starts the worker.
-4. `leave-planner.worker.ts` runs the framework-free core, sends progress and valid checkpoints, publishes the outcome first, then delivers its stable explanation and original trace.
+4. `leave-planner.worker.ts` runs the framework-free core, sends progress and valid checkpoints, publishes the outcome first, then delivers its stable explanation and final state.
 5. `CalendarYear` ignores stale calculations, renders the selected dates, reports remaining balances or errors, and records successful request-to-rendered-calendar timing for duration refinement.
 
-Calculations run until all objectives complete or the user cancels; there is no automatic elapsed-time cutoff. During preparation and optimization, Cancel interrupts the worker cooperatively and preserves its best jointly valid candidate as a cancelled, incomplete calculation. A cancellation before a valid candidate reports no plan. The final calendar is delivered before the explanation and complete original trace, whose later arrival or failure cannot change the retained plan. Worker heartbeats distinguish responsive long phases from a worker that stops responding. See [the cancellation mechanism and checks](docs/planner-cancellation.md).
+Calculations run until all objectives complete or the user cancels; there is no automatic elapsed-time cutoff. During preparation and optimization, Cancel interrupts the worker cooperatively and preserves its best jointly valid candidate as a cancelled, incomplete calculation. A cancellation before a valid candidate reports no plan. The final calendar is delivered before the stable explanation, whose later arrival or failure cannot change the retained plan. Worker heartbeats distinguish responsive long phases from a worker that stops responding. See [the cancellation mechanism and checks](docs/planner-cancellation.md).
 
-Technical callers may explicitly supply `deadlineMs`, a finite non-negative planning-work budget of any size. Omission means no deadline; the calendar and benchmark never supply one. This opt-in budget starts after calendar preparation and excludes trace capture, observer callbacks, and post-outcome artifact work. Expiry returns `PlanningIncomplete` with the latest valid checkpoint, if any, rather than a conflict. It is independent of worker liveness monitoring.
+Technical callers may explicitly supply `deadlineMs`, a finite non-negative planning-work budget of any size. Omission means no deadline; the calendar and benchmark never supply one. This opt-in budget starts after calendar preparation and excludes observer callbacks and post-outcome explanation work. Expiry returns `PlanningIncomplete` with the latest valid checkpoint, if any, rather than a conflict. It is independent of worker liveness monitoring.
 
 ## Planning model
 
@@ -86,7 +85,7 @@ All planning dates are normalized as `YYYY-MM-DD` calendar values in the Europe/
 
 Settings save a fixed start date and an inclusive last planning date. The planner's exclusive end is the following calendar date, so matching settings dates cover one day. Without saved dates, the default is today in Europe/Paris through the same date twelve months later, exclusive (February 29 uses February 28 in the following year). Invalid edits prevent calculation and preserve the last valid saved dates. Changes to dates, balances, and rules apply to the displayed calendar on the next explicit Calculate action.
 
-An indicative range beside Calculate follows the current dates, balances, and rules. Completed plans refine it locally for the current browser session using request-to-rendered-calendar time; later trace delivery is excluded. The range never stops a calculation. See [the duration model and measurement contract](docs/planning-duration.md).
+An indicative range beside Calculate follows the current dates, balances, and rules. Completed plans refine it locally for the current browser session using request-to-rendered-calendar time; later explanation delivery is excluded. The range never stops a calculation. See [the duration model and measurement contract](docs/planning-duration.md).
 
 ## Optimization pipeline
 
@@ -134,7 +133,7 @@ stateDiagram-v2
     Plan --> [*]
 ```
 
-`PlanningIncomplete` is reachable from every active calculation state. Cancellation retains the best available jointly valid candidate, even before a stage completes; completed stages also publish checkpoints for other interruption paths. An explicit technical deadline applies only after calendar preparation, while worker failure can interrupt any active phase. `PlanningConflict` is produced only when the obligations are valid but jointly infeasible. Outcome delivery does not wait for explanation or trace completion.
+`PlanningIncomplete` is reachable from every active calculation state. Cancellation retains the best available jointly valid candidate, even before a stage completes; completed stages also publish checkpoints for other interruption paths. An explicit technical deadline applies only after calendar preparation, while worker failure can interrupt any active phase. `PlanningConflict` is produced only when the obligations are valid but jointly infeasible. Outcome delivery does not wait for explanation completion.
 
 1. validate and normalize the request;
 2. find joint obligation assignments;
@@ -150,9 +149,9 @@ stateDiagram-v2
 
 Every placement records its source balance and all rules it satisfies. Remaining balances are classified as unavoidable expiry, at risk, or deferred.
 
-The calendar keeps plan details and the advanced trace collapsed initially. Plan details navigate final placements chronologically, showing provenance, contributions, the first decisive objective, and the full ordered comparison including obligation validity. **Compare dates** opens an on-demand hypothetical comparison across the submitted horizon, preserving the selected balance, type, and provenance without changing the plan.
+The calendar keeps plan details collapsed initially. Plan details navigate final placements chronologically, showing provenance, contributions, the first decisive objective, and the full ordered comparison including obligation validity. **Compare dates** opens an on-demand hypothetical comparison across the submitted horizon, preserving the selected balance, type, and provenance without changing the plan.
 
-The trace explorer navigates original phases and atomic decisions, expands candidate evaluations, and shows before/after calendar states. Historical date statuses remain separate from hypothetical results. Incomplete outcomes explain the retained plan and unfinished phases; conflicts identify the reported obligations and bottleneck. Controls support keyboard navigation, labelled dates, live announcements, and text or icons alongside color. Only the latest trace is retained locally in memory.
+Incomplete outcomes explain the retained plan and unfinished phases; conflicts identify the reported obligations and bottleneck. Remaining balances retain their classification, validity, earned-entitlement source and concrete displayed-plan reasons, without historical attempt lists. Controls support keyboard navigation, labelled dates, live announcements, and text or icons alongside color.
 
 ## Technical stack
 
@@ -223,7 +222,7 @@ Open <http://localhost:4200>. The development server reloads when source files c
 
 ## Performance benchmark
 
-Build or start the application, then open `/benchmark`. The isolated harness covers a representative year, typed obligations, chained earned entitlements, a deliberate conflict, a loaded year, and two- and three-year horizons with dated annual balances. It reports preparation time, planning latency, separate trace-delivery latency, total wall time, UI timer delay, available main-thread heap measurements, outcome, last completed stage, placement count, determinism, and trace size/status.
+Build or start the application, then open `/benchmark`. The isolated harness covers a representative year, typed obligations, chained earned entitlements, a deliberate conflict, a loaded year, and two- and three-year horizons with dated annual balances. It reports preparation time, planning latency, planning-work time, total wall time through explanation delivery, UI timer delay, available main-thread heap measurements, outcome, last completed stage, placement count, and determinism.
 
 The release protocol, recorded desktop measurements, and hardware limitations are documented in [docs/benchmark/README.md](docs/benchmark/README.md). No reference-phone run or multi-year duration ceiling is established; timing measurements are release evidence, not CI assertions.
 
@@ -287,6 +286,6 @@ Run `node scripts/ci-policy.test.mjs` and `node scripts/ci-image.test.mjs` local
 - [ADR 0001](docs/adr/0001-ordered-heuristic-optimization.md) records the ordered heuristic decision.
 - [ADR 0002](docs/adr/0002-personal-client-side-planner-for-now.md) records the client-side scope.
 - [ADR 0003](docs/adr/0003-constraint-first-lexicographic-planning.md) records the constraint-first planner architecture.
-- [ADR 0004](docs/adr/0004-stable-explanation-original-trace-counterfactual.md) separates the outcome, stable explanation, original trace, and hypothetical analysis.
+- [ADR 0004](docs/adr/0004-stable-explanation-original-trace-counterfactual.md) separates the outcome, stable explanation and displayed-placement hypothetical analysis.
 - [ADR 0005](docs/adr/0005-saved-planning-inputs-before-random-defaults.md) records saved-input restoration and random fallback behavior.
 - [ADR 0006](docs/adr/0006-user-selected-horizons-and-cancellable-calculations.md) records fixed saved horizons, cancellation, duration estimation, and the removal of the automatic deadline.

docs/adr/0004-separate-plan-explanation-from-calculation-trace.md

@@ -1,5 +1,7 @@
-# Separate Plan Explanations from Calculation Traces
+# Stable Plan Explanations Without Decision History
 
-The automatic planning deadline referenced below is superseded by [ADR 0006](0006-user-selected-horizons-and-cancellable-calculations.md), implemented by issue #59. Technical callers can still opt into an explicit planning-work budget; the user flow has no automatic cutoff.
+Issue #76 supersedes this ADR's original requirement to capture and deliver a complete calculation trace. The original decision trace, historical analysis, replay and candidate-history retention are removed end to end.
 
-VacOptimizer provides a stable plan explanation separately from the complete, untruncated calculation trace captured during the same planning run; on-demand counterfactual date analysis is identified as hypothetical and never presented as trace history. Explanation and tracing must not alter the planning outcome, so trace instrumentation is excluded from the planner deadline and the result may appear before the latest run's in-memory trace finishes loading; this narrows ADR 0003's ten-second hard limit to planning work rather than end-to-end trace delivery. This accepts additional transient memory and wall-clock time instead of inventing scalar day scores, truncating history, or reconstructing a trace by replay.
+The stable explanation describes the displayed plan, including valid incomplete incumbents: entitlement and rule provenance, contributions, the full ordered objective comparison and first decisive objective, time-off periods, remaining balances and concrete non-placement reasons. Invalid input and obligation conflicts retain their distinct explanations.
+
+Outcomes are delivered before explanation work. Explanation failures cannot discard an available outcome. Immutable calculation, valid-incumbent and final-state snapshots remain available for cancellation recovery and hypothetical analysis; they are independent of tracing. ADR 0006's opt-in technical planning-work budget excludes observer callbacks and post-outcome explanation work. The user flow has no automatic elapsed-time cutoff.

docs/adr/0004-stable-explanation-original-trace-counterfactual.md

@@ -1,11 +1,9 @@
-# Stable Explanation, Original Trace, and Counterfactuals
+# Stable Explanation and Displayed-Placement Counterfactuals
 
-The automatic planning deadline referenced below is superseded by [ADR 0006](0006-user-selected-horizons-and-cancellable-calculations.md), implemented by issue #59. Technical callers can still opt into an explicit planning-work budget; the user flow has no automatic cutoff.
+Issue #76 supersedes the original decision-trace and historical-counterfactual requirements of this ADR. Calculations no longer capture, retain or deliver decision history, and the UI has no trace explorer, replay, historical candidate statuses or balance-attempt lists.
 
-VacOptimizer exposes one client-side calculation context. Its immutable submitted snapshot and planning outcome are independent from three explanation concerns:
+VacOptimizer exposes one client-side calculation context with an immutable submitted configuration. Its outcome is independent from the stable explanation, which describes the final displayed plan and remains useful for complete and valid incumbent plans.
 
-- the stable plan explanation is derived from the final displayed plan and remains useful for complete or incumbent plans;
+Counterfactual date analysis tests a displayed placement over every date of the submitted half-open horizon. It uses the captured configuration and final-state snapshot, releases only that placement, preserves its entitlement, leave type and rule provenance, and fixes unrelated placements. Earned-entitlement chronology and all obligations still apply. The result is explicitly hypothetical and never mutates the displayed plan. Historical decisions are not selectable analysis baselines.
-- the calculation trace is captured while the producing run executes, grouped by phase and atomic decision, and may become ready after the outcome;
-- counterfactual date analysis is an explicitly hypothetical operation that removes only the selected final placement, or starts from a selected trace decision's exact pre-decision state, and never rewrites the plan or historical trace.
 
-The public planning outcome is delivered as soon as planning work finishes. Trace capture and delivery have separate readiness/failure state, remain local to the latest calculation, and cannot turn a valid outcome into an explanation error. Counterfactual work is cancellable or ignored when its calculation identity is stale. The existing deterministic constraint-first planner and its planning-work deadline remain unchanged.
+The public outcome is delivered as soon as planning work finishes. Explanation delivery failures cannot replace it. Counterfactual work is cancelled or ignored when its calculation identity is stale. Search breadth, allocation previews, user priorities, deterministic selection and ADR 0006's cancellation, liveness and technical-budget contracts remain unchanged. Workers finish after required outcome and explanation delivery without acknowledgement queues.

docs/adr/0006-user-selected-horizons-and-cancellable-calculations.md

@@ -1,17 +1,19 @@
 # User-Selected Horizons and Cancellable Calculations
 
-Accepted for [issue #12](https://gitea.nessar.fr/nessar/vac-optimizer/issues/12). Fixed, saved planning horizons are implemented by [issue #57](https://gitea.nessar.fr/nessar/vac-optimizer/issues/57); user cancellation with a retained valid plan and original trace is implemented by [issue #58](https://gitea.nessar.fr/nessar/vac-optimizer/issues/58); removal of the automatic calculation deadline and heartbeat-based worker liveness are implemented by [issue #59](https://gitea.nessar.fr/nessar/vac-optimizer/issues/59). The indicative duration estimate is implemented by [issue #60](https://gitea.nessar.fr/nessar/vac-optimizer/issues/60); its initial model, session-local refinement and calendar-rendering measurement are documented in [planning-duration.md](../planning-duration.md).
+Accepted for [issue #12](https://gitea.nessar.fr/nessar/vac-optimizer/issues/12). Fixed, saved planning horizons are implemented by [issue #57](https://gitea.nessar.fr/nessar/vac-optimizer/issues/57); user cancellation with a retained valid plan is implemented by [issue #58](https://gitea.nessar.fr/nessar/vac-optimizer/issues/58); removal of the automatic calculation deadline and heartbeat-based worker liveness are implemented by [issue #59](https://gitea.nessar.fr/nessar/vac-optimizer/issues/59). The indicative duration estimate is implemented by [issue #60](https://gitea.nessar.fr/nessar/vac-optimizer/issues/60); its initial model, session-local refinement and calendar-rendering measurement are documented in [planning-duration.md](../planning-duration.md).
 
-`deadlineMs` remains an opt-in contract for technical callers: a finite non-negative planning-work budget with no ten-second cap. An omitted value is unlimited. It starts after calendar preparation and excludes trace capture, observer callbacks, and post-outcome artifact work. The calendar and benchmark omit it. A one-second worker heartbeat renews the coordinator's thirty-second inactivity timer during cooperative preparation and search; total elapsed time never triggers that timer while activity continues. Worker errors and unavailable execution retain their explicit outcomes, and monitoring ends when the outcome arrives so delayed trace delivery cannot invalidate it.
+`deadlineMs` remains an opt-in contract for technical callers: a finite non-negative planning-work budget with no ten-second cap. An omitted value is unlimited. It starts after calendar preparation and excludes observer callbacks and post-outcome explanation work. The calendar and benchmark omit it. A one-second worker heartbeat renews the coordinator's thirty-second inactivity timer during cooperative preparation and search; total elapsed time never triggers that timer while activity continues. Worker errors and unavailable execution retain their explicit outcomes, and monitoring ends when the outcome arrives so delayed explanation delivery cannot invalidate it.
 
-VacOptimizer accepts explicitly selected, fixed planning horizons whose start may be past and whose duration may exceed twelve months, retaining today through the same date twelve months later as the default. Calculations remain in the browser and run to completion without an automatic elapsed-time cutoff, with an indicative duration estimate and an explicit Cancel action; this accepts variable waiting time and resource use to make longer horizons usable without silently changing the user's dates. This supersedes ADR 0003's ten-second automatic planning limit and its retention in both ADR 0004 documents, while preserving the separation between the planning outcome, stable explanation, and original trace.
+VacOptimizer accepts explicitly selected, fixed planning horizons whose start may be past and whose duration may exceed twelve months, retaining today through the same date twelve months later as the default. Calculations remain in the browser and run to completion without an automatic elapsed-time cutoff, with an indicative duration estimate and an explicit Cancel action; this accepts variable waiting time and resource use to make longer horizons usable without silently changing the user's dates. This supersedes ADR 0003's ten-second automatic planning limit and its retention in both ADR 0004 documents, while preserving the separation between the planning outcome and stable explanation.
 
 The planning-period control in Configure your leave uses an inclusive last planning date. The planner retains its half-open horizon by using the following calendar date as its exclusive end, matching the inclusive date-selection convention of TIME_WINDOW rules.
 
 Editing the horizon does not trigger a calculation. The user can adjust dates, balances, and rules before using the existing Calculate action; until a new calculation is requested, the displayed calendar retains its preceding outcome and horizon.
 
-A successful calculation displays the calendar once, as soon as the full planning objective order is complete, without displaying intermediate plans during optimization. Trace delivery continues in the background and never delays or changes that final calendar. The indicative duration estimate covers elapsed time until the final calendar is usable, including any trace capture that delays the outcome, rather than the additional time to deliver the complete trace.
+A successful calculation displays the calendar once, as soon as the full planning objective order is complete, without displaying intermediate plans during optimization. Stable explanation delivery follows the outcome and never changes that final calendar. The indicative duration estimate covers elapsed time until the final calendar is usable, excluding later explanation work.
 
 Before Calculate, the estimate is shown as an approximate range in seconds or minutes based on the horizon, balances, and rules. It starts with a rough estimate and is refined using measured calculation durations on the same device; it never becomes an automatic stopping deadline.
 
 User cancellation during optimization preserves the best valid plan already found and labels it as a cancelled, incomplete calculation. Before any valid plan exists, cancellation reports that the calculation was cancelled without presenting a plan or claiming an obligation conflict.
+
+Issue #76 supersedes all original-trace requirements in this ADR and both ADR 0004 documents. Decision capture, historical analysis and replay are removed. Immutable calculation, valid-incumbent and final-state snapshots remain for the retained explanation, cancellation recovery and displayed-placement counterfactuals. Cancellation still preserves the best available jointly valid plan and never implies an obligation conflict.

docs/benchmark/README.md

@@ -3,21 +3,27 @@
 ## Composable optimization rules: current verification status
 
 The #70–#75 implementation uses explicit active optimization configurations in
-the benchmark fixtures. The latest full functional coverage run passes 652 tests
+the benchmark fixtures. Before trace removal, the full functional coverage run passed 652 tests
 across 34 files under the 2 GB Node heap limit, excluding the separate benchmark.
-This does not establish a passing performance protocol.
+That run does not establish a passing performance protocol.
+
+On 2026-10-15, the #76 worktree based on `ea42561` passed 630 functional tests
+across 33 files with coverage under the 2 GB Node heap limit. Complete outcome
+comparisons against that baseline matched for all seven benchmark scenarios.
+The separate, unchanged benchmark did not complete within its 300-second limit
+(external timeout exit 124). Performance acceptance and any further optimization
+remain with #78.
 
 Before the Gitea migration, GitLab pipeline 320 passed all 652 functional tests
 in 109.43 seconds, then the seven-scenario protocol timed out at its unchanged
 300-second limit without an out-of-memory failure. In an earlier diagnostic run, the loaded-year warm-up took
 184.36 seconds and its first measured repetition began about 251.78 seconds into
 the protocol. Those diagnostic timings precede the final period-projection cache
-and the planned original-decision-trace removal, and are not a result for either.
+and the original-decision-trace removal in #76, and are not a result for either.
 
 At the user's request, #75 finishes on saved-rule migration and functional
 verification. #78 owns benchmark verification and implementation of further
-optimizations when needed, after #76 removes tracing and #77 verifies the retained
+optimizations when needed, after trace removal in #76 and integrated functional verification in #77. All seven scenarios, one warm-up and two measured repetitions per
-behavior. All seven scenarios, one warm-up and two measured repetitions per
 scenario, the 2 GB heap limit and the 300-second timeout remain required for #78.
 At the user's request, the Gitea CI configuration defines the benchmark in a
 separate job with `continue-on-error: true` while #78 is open. Functional coverage
@@ -30,7 +36,7 @@ workflow preserves the separate advisory benchmark job. See the
 [CI migration status](../../README.md#continuous-integration).
 
 The results below document earlier implementations and protocols. They are
-historical measurements rather than the performance result for composable rules.
+historical measurements rather than the performance result for composable rules or trace removal. Their trace counts, timings and controls describe the former implementation only.
 
 ## Reference-phone protocol
 
@@ -38,13 +44,9 @@ Open the deployed application at `/benchmark` on the reference phone. Tap
 **Run benchmark**, wait for the seven scenarios to finish, then tap **Copy
 report** and save the tab-separated output with the date and build identifier.
 
-The harness measures preparation, planning-to-outcome latency, later trace
+The harness measures preparation, planning-to-outcome latency, planning work, and total wall time through stable explanation delivery. It also reports the largest extra delay of a 50 ms UI heartbeat, available main-thread heap, outcome, last completed quality stage, placement count and determinism. `PlanningIncomplete` retains its last completed stage and valid incumbent and is distinct from a conflict.
-delivery, and total wall time separately. It also reports planning work, trace
+
-capture, trace materialization, and trace transfer independently, plus the
+Issue #76 removes all trace timing, status and candidate-count columns, along with trace promises and delivery requirements. The seven scenarios, warm-ups, repetitions, 2 GB heap limit, 300-second timeout and performance gates are unchanged. #77 owns integrated functional verification; #78 owns performance acceptance and any necessary optimization.
-largest extra delay of a 50 ms UI heartbeat. It records the outcome, last
-completed quality stage, placement count, determinism, trace status, and trace
-candidate count. `PlanningIncomplete` is not a conflict: its last completed
-stage and incumbent are retained.
 
 ## Protocol
 
@@ -67,23 +69,16 @@ stage and incumbent are retained.
 
 The browser page uses the same `createPlanningCalculation(request)` context as
 the calendar and adds no solver or backend dependency. It omits `deadlineMs`.
-Trace delivery is reported separately and cannot replace a valid planning outcome.
+Explanation delivery is independent of the outcome and cannot replace a valid plan.
 
-`planning_ms` is the observed latency until the outcome is usable;
+`planning_ms` is the observed latency until the outcome is usable. `planning_work_ms` excludes observer callbacks and post-outcome explanation work. `wall_ms` includes preparation, outcome and explanation delivery. `max_ui_delay_ms` covers this entire interval; there is no decision recording, trace materialization or trace transfer.
-`planning_work_ms` excludes trace capture. `trace_capture_ms` accounts for
-instrumentation during planning, `trace_materialization_ms` accounts for
-building the stable explanation and finishing the trace after the outcome.
-`trace_transfer_ms` measures worker transfer and receiver assembly work;
-`trace_delivery_ms` measures elapsed time until the complete trace is ready. `max_ui_delay_ms` includes
-planning, trace delivery, and report preparation. Trace readiness has no
-elapsed-time ceiling and never permits truncating actual candidate evaluations.
 
 `peak_main_thread_heap_bytes` is Chromium's available `performance.memory`
 sample, taken alongside the 50 ms UI heartbeat. A blank value means this API is
 unavailable. This measures the page's JS heap, excludes the worker heap, and is
 not a claim about total application memory. For a browser profile, record the
 isolated Chrome process-tree RSS separately during planning and subsequent
-trace delivery, including the worker and renderer. State the sampling interval,
+explanation delivery, including the worker and renderer. State the sampling interval,
 CPU throttling, viewport, and whether a warm-up preceded each measurement.
 
 For cancellation measurements, use the normal calendar with the same saved
@@ -91,11 +86,15 @@ two- or three-year dates and balances. Cancel during preparation and an active
 optimization phase, using the keyboard in one run. Record request-to-outcome
 latency separately from request-to-artifacts latency; verify the partial-plan
 status or absence of a plan, one planning request, no placements before the
-outcome, and continued acknowledged delivery of the original trace. Confirm
+outcome, and delivery of its stable explanation. Confirm
 that editing an input remains possible during active worker CPU work. These
 measurements describe that device and workload; they impose no latency limit.
 
-## Hardware status
+## Historical measurements before trace removal
+
+The following records remain as evidence for their dated builds. Trace-related behavior and metrics below are superseded by issue #76.
+
+### Hardware status
 
 No reference-phone run has been recorded. The project owner elected to close
 the release tickets on 2026-09-25 using the emulated run below, accepting its

docs/planner-cancellation.md

@@ -1,6 +1,6 @@
 # Cancelling a planning calculation
 
-Issue [#58](https://gitea.nessar.fr/nessar/vac-optimizer/issues/58) implements the cancellation portion of ADR 0006. Issue #59 removes the automatic deadline while keeping the same cancellation and original-trace protocol. The duration estimate remains in issue #60.
+Issue [#58](https://gitea.nessar.fr/nessar/vac-optimizer/issues/58) implements the cancellation portion of ADR 0006. Issue #59 removes the automatic deadline. Issue #76 removes decision tracing while preserving cancellation and valid-plan recovery. The duration estimate remains in issue #60.
 
 `PlanningCalculationContext.cancel()` requests user cancellation once while its outcome is pending. `CalendarYear` keeps an accessible Cancel button visible during preparation, obligation search, and optimization. It announces the request, disables duplicate cancellation, and moves keyboard focus to the result heading when the outcome arrives. Cancellation never triggers Calculate. A subsequent explicit Calculate creates a fresh immutable calculation snapshot.
 
@@ -10,25 +10,25 @@ The core exposes resumable generator steps. `calculatePlanningAsyncInternal` dri
 
 The synchronous `calculatePlanningInternal` adapter drains the same steps without pauses for existing direct core callers. The public non-browser calculation context uses the asynchronous driver so its cancellation method also works.
 
-User cancellation is distinct from replacement by another calculation (`stale-calculation`) and isolated worker failure (`worker-error` or `worker-unavailable`). Replacement retains the existing termination and stale-response protection. User cancellation leaves the producing worker alive until its explanation and trace have been delivered.
+User cancellation is distinct from replacement by another calculation (`stale-calculation`) and isolated worker failure (`worker-error` or `worker-unavailable`). Replacement retains the existing termination and stale-response protection. User cancellation leaves the producing worker alive until its outcome and explanation data have been delivered.
 
 ## Retaining a valid plan
 
-The asynchronous calculation retains a copied incumbent as soon as the obligation search finds a jointly valid solution, before that entire stage has completed. It also considers accepted placements and every feasible evaluated quality candidate, including candidates rejected by a stage's narrower comparator. Each candidate is reconciled for earned entitlement availability and checked against all obligation rules before retention. The existing full lexicographic comparator chooses the best available incumbent; its comparisons are recorded in the original trace.
+The asynchronous calculation retains a copied incumbent as soon as the obligation search finds a jointly valid solution, before that entire stage has completed. It also considers accepted placements and every feasible evaluated quality candidate, including candidates rejected by a stage's narrower comparator. Each candidate is reconciled for earned entitlement availability and checked against all obligation rules before retention. The existing full lexicographic comparator chooses the best available incumbent.
 
-Retention reuses quality metrics already computed for an evaluated candidate. An intermediate state with more unplaced at-risk leave, or worse preferences at equal unplaced leave, is rejected using that objective prefix alone, with the actual short-circuited comparison recorded in the trace. This avoids rescoring dominated states during large obligation previews without skipping any produced history or a candidate that could improve the retained plan.
+Retention reuses quality metrics already computed for an evaluated candidate. An intermediate state with more unplaced at-risk leave, or worse preferences at equal unplaced leave, is rejected using that objective prefix alone. This avoids rescoring dominated states during large obligation previews without skipping a candidate that could improve the retained plan.
 
-Preference occurrence dates and patterns are calculated once for the run's immutable calendar and rules. Each comparison still checks the candidate's actual placements against those patterns; candidate scores and trace records are not cached.
+Preference occurrence dates and patterns are calculated once for the run's immutable calendar and rules. Each comparison still checks the candidate's actual placements against those patterns; candidate scores are not cached.
 
 On cancellation, the core materializes the retained state with consistent placements, balances, periods, rule provenance, and preference satisfaction. It returns `PlanningIncomplete` with reason `user-cancelled`. With an incumbent the French status is **Calcul annulé — plan partiel**; without one it is **Calcul annulé**, without a plan or an obligation conflict. Temporary search states never become the displayed incumbent.
 
-## Preserving the original trace
+## Delivering the outcome and explanation
 
-Cancellation follows the core's normal finish path. Quality evaluations are recorded before their incumbent comparisons, and each greedy placement attempt starts its own atomic decision. The recorder closes interrupted and unexecuted phases and drains every remaining operation from that run. The worker retains staged updates, including ones not yet posted, and continues its bounded, acknowledged trace delivery after optimization has stopped. It sends `artifacts-complete` only when all queued updates have been sent and acknowledged. The facade drains its own received update queue before resolving the trace. Neither layer replays planning to reconstruct this history.
+Cancellation follows the normal finish path. The stable explanation is derived from the retained state. Outcome and explanation have separate promises: delayed or failed explanation delivery cannot replace or remove an already settled valid partial plan. Repeated and late outcome messages cannot change that outcome, and calculation identities protect the UI against obsolete results and explanations.
 
-The stable explanation is derived from the retained state. The outcome, explanation, and trace have separate promises: delayed or failed artifact delivery cannot replace or remove an already settled valid partial plan. Repeated and late outcome messages cannot change that outcome, and calculation identities protect the UI against obsolete results and artifacts.
+Immutable `PlanningStateSnapshot` values preserve exact entitlement metadata, earned activations, declarations and placements for checkpoints and the final state. A worker failure retains the latest delivered valid checkpoint and can recover its stable explanation in a separate worker without rerunning planning. Displayed-placement alternatives use the captured configuration and state; no original decisions or historical baselines are retained.
 
-If Cancel is accepted just before a queued natural result reaches the facade, the pending outcome still becomes a user cancellation. An already computed valid plan can be retained, while a queued conflict cannot become the cancellation result. Its existing explanation receives interruption metadata, and the original phase history is preserved even when the worker had already completed those phases.
+If Cancel is accepted just before a queued natural result reaches the facade, the pending outcome still becomes a user cancellation. An already computed valid plan can be retained, while a queued conflict cannot become the cancellation result. Its existing explanation receives interruption metadata. The planning worker terminates after delivering the required artifacts; it never waits for trace acknowledgements.
 
 ## Verification
 
@@ -42,10 +42,10 @@ bunx tsc --noEmit -p tsconfig.app.json
 bunx tsc --noEmit -p tsconfig.spec.json
 ```
 
-The public cancellation tests cover immediate cancellation, queued trace updates on both sides of the request, a stable partial outcome despite late completion or artifact error, distinct worker failure and replacement (including non-browser explanation metadata), and cancellation after settlement. A core regression compares the retained plan's full objective vector with every valid candidate actually evaluated before cancellation. The CalendarYear tests cover keyboard activation, translated statuses with and without an incumbent, focus, no implicit recalculation, explicit recalculation, and obsolete trace delivery.
+The public cancellation tests cover immediate cancellation, a stable partial outcome despite late completion or artifact error, distinct worker failure and replacement (including non-browser explanation metadata), and cancellation after settlement. Core regressions verify retained validity, provenance, earned chronology and the best available partial plan through the existing checkpoint seam. The CalendarYear tests cover keyboard activation, translated statuses with and without an incumbent, focus, no implicit recalculation, explicit recalculation, and obsolete explanation delivery.
 
-The real-worker suite bundles the production worker source with Bun and runs it on a separate Node worker thread. Its small host adapter maps browser worker messages to the thread's message port; the planner, CPU work, cancellation handling, and acknowledged trace protocol are real. It checks interruption after preparation has started, before the first obligation solution, during active obligation CPU work after a solution exists, and after a completed checkpoint. It also compares an uncancelled outcome with the synchronous adapter's deterministic result. These checks complement the controlled worker boundary tests.
+The real-worker suite bundles the production worker source with Bun and runs it on a separate Node worker thread. Its small host adapter maps browser worker messages to the thread's message port; the planner, CPU work, cancellation handling, and outcome and explanation delivery protocol are real. It checks interruption after preparation has started, before the first obligation solution, during active obligation CPU work after a solution exists, and after a completed checkpoint. It also compares an uncancelled outcome with the synchronous adapter's deterministic result. These checks complement the controlled worker boundary tests.
 
-For a browser check, serve the production browser build and use native Chromium Web Workers with a saved annual horizon. Check cancellation during calendar preparation, a broad obligation search, and a quality pass. Confirm one planning request per Calculate, no new request on Cancel, the appropriate translated status, joint rule satisfaction and balance accounting for an incumbent, and complete trace delivery after the outcome. Also check the Cancel control with the keyboard, at 375px width, and in light and dark themes.
+For a browser check, serve the production browser build and use native Chromium Web Workers with a saved annual horizon. Check cancellation during calendar preparation, a broad obligation search, and a quality pass. Confirm one planning request per Calculate, no new request on Cancel, the appropriate translated status, joint rule satisfaction and balance accounting for an incumbent, and stable explanation delivery after the outcome. Also check the Cancel control with the keyboard, at 375px width, and in light and dark themes.
 
-The production build was checked in native Chromium for all three interruption points, including keyboard cancellation during a 375px dark-theme obligation search and desktop light-theme checks. An editable input could still receive focus during CPU work, and focus moved to the result heading after keyboard cancellation. Each run sent one planning request and one cancellation request, displayed the appropriate French status, and completed acknowledged artifact delivery. The Cancel control was 44px high and the page had no horizontal overflow. In these sample runs, cancellation through artifact completion took under 200ms; this is measured evidence, not a latency guarantee.
+Earlier browser checks before #76: the production build was checked in native Chromium for all three interruption points, including keyboard cancellation during a 375px dark-theme obligation search and desktop light-theme checks. An editable input could still receive focus during CPU work, and focus moved to the result heading after keyboard cancellation. Each run sent one planning request and one cancellation request, displayed the appropriate French status, and completed acknowledged artifact delivery. The Cancel control was 44px high and the page had no horizontal overflow. In these sample runs, cancellation through artifact completion took under 200ms; this is measured evidence, not a latency guarantee.

docs/planning-duration.md

@@ -79,13 +79,12 @@ The existing initial calculation falls back to the start of `startCalculation`.
 The endpoint is Angular's `afterNextRender` callback after the complete plan has
 been projected into the calendar, its months and placements have been rendered,
 and the loading overlay has been removed. This measures request scheduling,
-calendar preparation, worker startup, search, trace capture that delays the
+calendar preparation, worker startup, search, outcome transport, projection and Angular rendering. It is a DOM
-outcome, outcome transport, projection and Angular rendering. It is a DOM
 readiness endpoint, rather than a claim to measure a physical screen's paint.
 
 Neither core `planningWorkMs` nor artifact timings supply the calibration
-measurement. The callback does not wait for the explanation or trace promises;
+measurement. The callback does not wait for the explanation promise;
-later delivery, navigation and trace errors never add a second measurement.
+later delivery, navigation and explanation errors never add a second measurement.
 Cancellation (including a retained incumbent), incomplete outcomes, invalid
 inputs, conflicts and calculation errors do not calibrate successful-plan
 waiting time. Superseded calculations and callbacks for destroyed calendars
@@ -98,12 +97,12 @@ timer, date adjustment or new calculation. **Cancel** remains explicit.
 
 Controlled-clock tests at the existing calendar and input seams cover initial
 estimation, unsubmitted edits, minute formatting, local refinement, request
-scheduling, a twenty-second calculation exceeding its initial range, a trace
+scheduling, a twenty-second calculation exceeding its initial range, an explanation
-that fails five minutes after calendar readiness, cancellation with and without
+that arrives after calendar readiness, cancellation with and without
 an incumbent, incomplete/error outcomes and superseded calculations. No timing
 assertion depends on CI hardware speed. Existing settings, planner and worker
-tests cover saved horizons, long calculations and original interrupted traces.
+tests cover saved horizons, long calculations and interrupted-plan explanations.
 
 Rendered annual, two-year and three-year references, with the actual displayed
-range and separate later trace wait, are recorded in
+range and historical artifact-delivery wait, are recorded in
 [the benchmark report](benchmark/README.md).

src/app/benchmark/leave-planner-benchmark.spec.ts

@@ -9,7 +9,7 @@ import {
 describe('leave planner benchmark protocol', () => {
 	beforeEach(() => vi.setSystemTime(new Date('2024-01-01T12:00:00Z')));
 	afterEach(() => vi.useRealTimers());
-	// Warm-up and two repetitions include complete trace delivery after planning.
+	// Warm-up and two repetitions include explanation delivery after planning.
 	it('keeps seven deterministic scenarios including two and three years and a later earned consumer', async () => {
 		const scenarios = benchmarkScenarios();
 		expect(scenarios).toHaveLength(7);
@@ -75,8 +75,6 @@ describe('leave planner benchmark protocol', () => {
 				expect(longer.map((item) => item.lastCompletedStage)).toEqual(['dates', 'dates']);
 				expect(longer.map((item) => item.placements)).toEqual([placements, placements]);
 				expect(longer.map((item) => item.deterministic)).toEqual(['baseline', 'yes']);
-				expect(longer.map((item) => item.traceStatus)).toEqual(['ready', 'ready']);
-				expect(longer[0].traceCandidates).toBeGreaterThan(0);
 			}
 			const chained = measurements.find(
 				(measurement) => measurement.scenario === 'chained earned entitlements',
@@ -91,21 +89,16 @@ describe('leave planner benchmark protocol', () => {
 			expect(loaded[0].deterministic).toBe('baseline');
 			expect(loaded[1].deterministic).toBe('yes');
 			expect(loaded[0].planningMs).toBeGreaterThanOrEqual(0);
-			expect(loaded[0].traceDeliveryMs).toBeGreaterThanOrEqual(0);
 			expect(loaded[0].planningWorkMs).toBeGreaterThanOrEqual(0);
 			expect(loaded[0].planningWorkMs).toBeLessThanOrEqual(loaded[0].planningMs);
-			expect(loaded[0].traceCaptureMs).toBeGreaterThan(0);
-			expect(loaded[0].traceMaterializationMs).toBeGreaterThanOrEqual(0);
 			expect(loaded[0].maxUiDelayMs).toBeGreaterThanOrEqual(0);
 			expect(loaded[0].wallMs).toBeGreaterThanOrEqual(
-				loaded[0].preparationMs + loaded[0].planningMs + loaded[0].traceDeliveryMs,
+				loaded[0].preparationMs + loaded[0].planningMs,
 			);
-			expect(loaded[0].traceStatus).toBe('ready');
-			expect(loaded[0].traceCandidates).toBeGreaterThan(0);
 			const report = benchmarkReport(measurements);
 			expect(report.split('\n')).toHaveLength(15);
-			expect(report).toContain('planning_ms\ttrace_delivery_ms');
+			expect(report).toContain('planning_ms\twall_ms');
-			expect(report).toContain('planning_work_ms\ttrace_capture_ms');
+			expect(report).toContain('planning_work_ms\tpeak_main_thread_heap_bytes');
 			expect(report).toContain('\tbaseline\t');
 		} finally {
 			vi.stubGlobal('window', browserWindow);

src/app/benchmark/leave-planner-benchmark.ts

@@ -2,7 +2,6 @@ import {
 	createPlanningCalculation,
 	PlanningOutcome,
 	PlanningRequest,
-	PlanningTrace,
 } from '../services/leave-planner.service';
 import { createOptimizationPresetRules } from '../services/rule-service';
 
@@ -16,21 +15,15 @@ export interface BenchmarkMeasurement {
 	repetition: number;
 	preparationMs: number;
 	planningMs: number;
-	traceDeliveryMs: number;
 	maxUiDelayMs: number;
 	/** Chromium's main-thread heap only; worker memory needs a separate browser profile. */
 	peakMainThreadHeapBytes?: number;
 	planningWorkMs?: number;
-	traceCaptureMs?: number;
-	traceMaterializationMs?: number;
-	traceTransferMs?: number;
 	wallMs: number;
 	outcome: PlanningOutcome['kind'];
 	lastCompletedStage?: string;
 	placements: number;
 	deterministic: 'baseline' | 'yes' | 'no';
-	traceStatus: PlanningTrace['status'] | 'not-produced';
-	traceCandidates: number;
 }
 
 const balance = (
@@ -219,7 +212,8 @@ export async function runLeavePlannerBenchmark(repetitions = 1): Promise<Benchma
 async function warmUpScenario(scenario: BenchmarkScenario): Promise<void> {
 	const calculation = createPlanningCalculation(structuredClone(scenario.request));
 	await calculation.outcome;
-	await calculation.trace;
+	await calculation.explanation;
+	await calculation.timings;
 }
 
 async function measureRepetition(
@@ -250,24 +244,11 @@ async function measureRepetition(
 		const calculation = createPlanningCalculation(request);
 		const outcome = await calculation.outcome;
 		const planningMs = performance.now() - calculationStart;
-		const traceStart = performance.now();
-		const trace = await calculation.trace;
-		const traceDeliveryMs = performance.now() - traceStart;
 		const timings = await calculation.timings;
 		const summary = resultSummary(outcome);
 		const stable = JSON.stringify(outcome);
 		const deterministic =
 			baseline === undefined ? 'baseline' : stable === baseline ? 'yes' : 'no';
-		const traceCandidates =
-			trace?.phases.reduce(
-				(total, phase) =>
-					total +
-					phase.decisions.reduce(
-						(decisionTotal, decision) => decisionTotal + decision.candidates.length,
-						0,
-					),
-				0,
-			) ?? 0;
 		const wallMs = performance.now() - wallStart;
 		measureDelay();
 		return {
@@ -276,15 +257,12 @@ async function measureRepetition(
 				repetition,
 				preparationMs,
 				planningMs,
-				traceDeliveryMs,
 				maxUiDelayMs,
 				peakMainThreadHeapBytes,
 				...timings,
 				wallMs,
 				...summary,
 				deterministic,
-				traceStatus: trace?.status ?? 'not-produced',
-				traceCandidates,
 			},
 			stable,
 		};
@@ -295,7 +273,7 @@ async function measureRepetition(
 
 export function benchmarkReport(measurements: BenchmarkMeasurement[]): string {
 	const header =
-		'scenario\trepetition\tpreparation_ms\tplanning_ms\ttrace_delivery_ms\twall_ms\toutcome\tlast_stage\tplacements\tdeterministic\ttrace_status\ttrace_candidates\tmax_ui_delay_ms\tplanning_work_ms\ttrace_capture_ms\ttrace_materialization_ms\ttrace_transfer_ms\tpeak_main_thread_heap_bytes';
+		'scenario\trepetition\tpreparation_ms\tplanning_ms\twall_ms\toutcome\tlast_stage\tplacements\tdeterministic\tmax_ui_delay_ms\tplanning_work_ms\tpeak_main_thread_heap_bytes';
 	return [
 		header,
 		...measurements.map((item) =>
@@ -304,19 +282,13 @@ export function benchmarkReport(measurements: BenchmarkMeasurement[]): string {
 				item.repetition,
 				item.preparationMs.toFixed(1),
 				item.planningMs.toFixed(1),
-				item.traceDeliveryMs.toFixed(1),
 				item.wallMs.toFixed(1),
 				item.outcome,
 				item.lastCompletedStage ?? '',
 				item.placements,
 				item.deterministic,
-				item.traceStatus,
-				item.traceCandidates,
 				item.maxUiDelayMs.toFixed(1),
 				item.planningWorkMs?.toFixed(1) ?? '',
-				item.traceCaptureMs?.toFixed(1) ?? '',
-				item.traceMaterializationMs?.toFixed(1) ?? '',
-				item.traceTransferMs?.toFixed(1) ?? '',
 				item.peakMainThreadHeapBytes ?? '',
 			].join('\t'),
 		),

src/app/components/calendar-month/calendar-month.html

@@ -29,7 +29,6 @@
 						} @else {
 							@let dayTooltip = getDayTooltip(day);
 							@let dateKey = getDateKey(day);
-							@let status = getStatus(day);
 							@let declaredType = getDeclaredType(dateKey);
 							@let previewed = declarationPreview?.dates?.has(dateKey);
 							<button
@@ -45,18 +44,6 @@
 								[class.declared]="!!declaredType"
 								[class.declaration-preview]="previewed"
 								[class.declaration-erase]="previewed && !declaredType"
-								[class.eligible]="status?.kind === 'eligible'"
-								[class.ineligible]="status?.kind === 'ineligible'"
-								[class.chosen]="status?.kind === 'chosen'"
-								[class.evaluated-rejected]="status?.kind === 'evaluated-rejected'"
-								[class.pruned]="status?.kind === 'pruned'"
-								[class.not-examined]="status?.kind === 'not-examined'"
-								[class.change-added]="status?.change === 'added'"
-								[class.change-moved-from]="status?.change === 'moved-from'"
-								[class.change-moved-to]="status?.change === 'moved-to'"
-								[class.change-removed]="status?.change === 'removed'"
-								[class.change-shared]="status?.change === 'shared'"
-								[class.change-unchanged]="status?.change === 'unchanged'"
 								[class]="getDayClasses(day)"
 								class="day number"
 								[disabled]="isDateDisabled(day)"
@@ -70,16 +57,6 @@
 								(click)="dateSelected.emit(dateKey)"
 							>
 								<span>{{ day.getDate() }}</span>
-								@if (status) {
-									<small class="status-marker" aria-hidden="true">{{
-										getStatusMarker(day)
-									}}</small>
-									@if (status.hypotheticalLabel) {
-										<small class="hypothetical-marker" aria-hidden="true">{{
-											getHypotheticalMarker(status)
-										}}</small>
-									}
-								}
 							</button>
 						}
 					}

src/app/components/calendar-month/calendar-month.scss

@@ -108,31 +108,6 @@
 		}
 	}
 
-	.status-marker {
-		position: absolute;
-		inset-block-start: -0.35rem;
-		inset-inline-end: -0.2rem;
-		min-width: 0.85rem;
-		font-size: 0.65rem;
-		font-weight: 800;
-		line-height: 1;
-		background: var(--ui-card-bg, #fff);
-		border-radius: 999px;
-	}
-
-	.hypothetical-marker {
-		position: absolute;
-		inset-block-end: -0.35rem;
-		inset-inline-start: -0.2rem;
-		min-width: 1.25rem;
-		font-size: 0.55rem;
-		font-weight: 800;
-		line-height: 1;
-		background: var(--ui-card-bg, #fff);
-		border: 1px dashed currentColor;
-		border-radius: 999px;
-	}
-
 	.current {
 		outline: 2px solid var(--today-border-color);
 		outline-offset: -2px;
@@ -142,43 +117,6 @@
 		box-shadow: inset 0 -3px var(--today-border-color);
 	}
 
-	.eligible,
-	.chosen {
-		border-block-end: 3px solid var(--ui-success-text, #174d26);
-	}
-
-	.ineligible,
-	.evaluated-rejected {
-		text-decoration: line-through;
-		text-decoration-thickness: 2px;
-	}
-
-	.pruned {
-		border: 2px dotted currentColor;
-	}
-
-	.not-examined {
-		border: 2px dashed currentColor;
-	}
-
-	.change-added,
-	.change-moved-to {
-		box-shadow: inset 0 -3px var(--ui-success-text, #174d26);
-	}
-
-	.change-moved-from,
-	.change-removed {
-		box-shadow: inset 0 3px var(--ui-error-text, #8b1a1a);
-	}
-
-	.change-shared {
-		box-shadow: inset 3px 0 var(--today-border-color, #1976d2);
-	}
-
-	.change-unchanged {
-		box-shadow: inset 0 0 0 1px currentColor;
-	}
-
 	.selected {
 		cursor: pointer;
 	}

src/app/components/calendar-month/calendar-month.ts

@@ -15,16 +15,6 @@ import { TranslationService } from '../../services/translation-service';
 import { isWorkingPlanningDate } from '../../services/declared-non-working-days';
 import type { LeaveType } from '../../services/leave-planner.service';
 
-export interface CalendarDayStatus {
-	kind: 'eligible' | 'ineligible' | 'chosen' | 'evaluated-rejected' | 'pruned' | 'not-examined';
-	label: string;
-	reason?: string;
-	hypotheticalLabel?: string;
-	hypotheticalReason?: string;
-	change?: 'added' | 'moved-from' | 'moved-to' | 'removed' | 'shared' | 'unchanged';
-	changeLabel?: string;
-}
-
 export interface DeclarationPreview {
 	dates: ReadonlySet<string>;
 	type: LeaveType | null;
@@ -112,9 +102,6 @@ export class CalendarMonth implements OnInit {
 	@Input()
 	explainedPeriod?: { start: string; end: string };
 
-	@Input()
-	dateStatuses: Readonly<Record<string, CalendarDayStatus>> = {};
-
 	@Output()
 	readonly dateSelected = new EventEmitter<string>();
 
@@ -134,10 +121,6 @@ export class CalendarMonth implements OnInit {
 		);
 	}
 
-	getStatus(day: Date): CalendarDayStatus | undefined {
-		return this.dateStatuses[this.getDateKey(day)];
-	}
-
 	isInExplainedPeriod(day: Date): boolean {
 		const date = this.getDateKey(day);
 		return (
@@ -147,44 +130,6 @@ export class CalendarMonth implements OnInit {
 		);
 	}
 
-	getStatusMarker(day: Date): string {
-		switch (this.getStatus(day)?.change) {
-			case 'added':
-				return '+';
-			case 'moved-from':
-				return '←';
-			case 'moved-to':
-				return '→';
-			case 'removed':
-				return '−';
-			case 'shared':
-				return '≈';
-			case 'unchanged':
-				return '=';
-		}
-		switch (this.getStatus(day)?.kind) {
-			case 'chosen':
-			case 'eligible':
-				return '✓';
-			case 'ineligible':
-				return '×';
-			case 'evaluated-rejected':
-				return '−';
-			case 'pruned':
-				return '⌁';
-			case 'not-examined':
-				return '?';
-			default:
-				return '';
-		}
-	}
-
-	getHypotheticalMarker(status: CalendarDayStatus): string {
-		return status.hypotheticalLabel === this.translationService.tr().planning.eligible
-			? '~✓'
-			: '~×';
-	}
-
 	getDayAriaLabel(day: Date, tooltip: string | null = this.getDayTooltip(day)): string {
 		const locale = this.translationService.locale();
 		if (!this.dayFormatter || locale !== this.dayFormatterLocale) {
@@ -252,20 +197,6 @@ export class CalendarMonth implements OnInit {
 			tooltips.push(
 				`${this.tr().bookedDays.booked} (${this.declaredTypeLabel(declaredType)}). ${this.tr().bookedDays.fixed}`,
 			);
-		const status = this.getStatus(day);
-		if (status) {
-			tooltips.push(status.label);
-			if (status.changeLabel) tooltips.push(status.changeLabel);
-			if (status.reason) tooltips.push(status.reason);
-			if (status.hypotheticalLabel)
-				tooltips.push(
-					`${this.translationService.tr().planning.counterfactual}: ${status.hypotheticalLabel}`,
-				);
-			if (status.hypotheticalReason)
-				tooltips.push(
-					`${this.translationService.tr().planning.reason}: ${status.hypotheticalReason}`,
-				);
-		}
 		return tooltips.length > 0 ? tooltips.join(' + ') : null;
 	}
 

src/app/components/calendar-year/calendar-year-planning.spec.ts

@@ -14,7 +14,6 @@ import {
 import {
 	CounterfactualAnalysis,
 	CounterfactualSelection,
-	HistoricalEligibilityReason,
 	LeavePlacement,
 	PlanOutcome,
 	PlanExplanation,
@@ -25,8 +24,6 @@ import {
 	InvalidInputOutcome,
 	PlanningOutcome,
 	PlanningObjectiveVector,
-	PlanningTrace,
-	PlanningTraceUpdate,
 } from '../../services/leave-planner.service';
 import { UserInputService } from '../../services/user-input-service';
 import { CalendarSettingsService } from '../../services/calendar-settings-service';
@@ -147,14 +144,12 @@ function placementForSelection(selection: CounterfactualSelection): LeavePlaceme
 				(candidate) => candidate.date === selection || candidate.balanceId === selection,
 			) ?? plan.placements[0]
 		);
-	return 'decisionId' in selection ? selection.placement : selection;
+	return selection;
 }
 
 function calculationFor(
 	outcome: PlanningOutcome,
 	stableExplanation?: PlanningExplanation,
-	trace?: PlanningTrace,
-	tracePromise: Promise<PlanningTrace | undefined> = Promise.resolve(trace),
 ): PlanningCalculationContext {
 	const counterfactual: CounterfactualAnalysis = {
 		kind: 'Counterfactual',
@@ -175,7 +170,6 @@ function calculationFor(
 				date: '2024-05-04',
 				status: 'ineligible',
 				reason: { code: 'non-working', message: 'Weekend' },
-				historicalStatus: 'ineligible',
 			},
 			{
 				date: '2024-05-07',
@@ -186,7 +180,6 @@ function calculationFor(
 				date: '2024-05-08',
 				status: 'ineligible',
 				reason: { code: 'non-working', message: 'Public Holiday' },
-				historicalStatus: 'ineligible',
 			},
 		],
 	};
@@ -203,27 +196,15 @@ function calculationFor(
 		outcome: Promise.resolve(outcome),
 		explanation: Promise.resolve(stableExplanation),
 		explanationError: Promise.resolve(undefined),
-		trace: tracePromise,
 		analyzeCounterfactual: vi.fn(async (selection: CounterfactualSelection) => ({
 			...counterfactual,
 			placement: placementForSelection(selection),
 		})),
-		historicalEligibility: vi.fn(async () => [] as readonly HistoricalEligibilityReason[]),
 	};
 }
 
-function calendarFor(
+function calendarFor(outcome: PlanningOutcome, stableExplanation?: PlanningExplanation) {
-	outcome: PlanningOutcome,
+	const calculation = calculationFor(outcome, stableExplanation);
-	stableExplanation?: PlanningExplanation,
-	trace?: PlanningTrace,
-	tracePromise?: Promise<PlanningTrace | undefined>,
-) {
-	const calculation = calculationFor(
-		outcome,
-		stableExplanation,
-		trace,
-		tracePromise ?? Promise.resolve(trace),
-	);
 	return {
 		calculation,
 		calendar: {
@@ -253,161 +234,6 @@ function activateWithKeyboard(element: HTMLElement, key: 'Enter' | ' ' = 'Enter'
 	element.click();
 }
 
-function jointTrace(): PlanningTrace {
-	const placementComparison =
-		explanation.kind === 'PlanExplanation' ? explanation.placements[0].comparison : undefined;
-	return {
-		status: 'ready',
-		initialState: {
-			horizon: plan.horizon,
-			balances: [
-				{
-					id: 'cp',
-					type: 'cp',
-					quantity: 2,
-					remaining: 2,
-					availableFrom: '2024-01-01',
-					expiryDate: '2024-12-31',
-					earned: false,
-				},
-				{
-					id: 'earned:spring:2024',
-					type: 'rtt',
-					quantity: 2,
-					remaining: 2,
-					availableFrom: '2024-05-04',
-					expiryDate: '2025-05-04',
-					earned: true,
-					sourceRuleId: 'spring',
-				},
-			],
-			placements: [plan.placements[1]],
-			earnedActivations: [
-				{
-					id: 'earned:spring:2024',
-					ruleId: 'spring',
-					occurrence: '2024',
-					dates: ['2024-05-03', '2024-05-06'],
-				},
-			],
-		},
-		phases: [
-			{
-				id: 'phase:obligations',
-				name: 'obligations',
-				completed: true,
-				status: 'completed',
-				decisions: [
-					{
-						id: 'decision:prior',
-						action: 'validate',
-						dates: ['2024-05-01'],
-						candidates: [],
-						deltas: [
-							{
-								kind: 'balance-changed',
-								balanceId: 'cp',
-								remainingBefore: 2,
-								remainingAfter: 1,
-							},
-						],
-					},
-					{
-						id: 'decision:joint',
-						action: 'choose',
-						dates: ['2024-05-03', '2024-05-06'],
-						branch: {
-							parentDecisionId: 'decision:prior',
-							deltas: [
-								{
-									kind: 'placement-added',
-									date: '2024-05-03',
-									balanceId: 'cp',
-									remainingBefore: 1,
-									remainingAfter: 0,
-									placement: plan.placements[0],
-								},
-								{
-									kind: 'balance-changed',
-									balanceId: 'earned:spring:2024',
-									remainingBefore: 2,
-									remainingAfter: 2,
-									balance: {
-										id: 'earned:spring:2024',
-										type: 'rtt',
-										quantity: 2,
-										remaining: 2,
-										availableFrom: '2024-05-07',
-										expiryDate: '2025-05-07',
-										earned: true,
-										sourceRuleId: 'spring',
-									},
-								},
-							],
-						},
-						candidates: [
-							{
-								status: 'evaluated-rejected',
-								dates: ['2024-05-10', '2024-05-13'],
-								reason: {
-									code: 'joint-date-conflict',
-									message: 'This branch cannot satisfy both required dates.',
-								},
-								technicalComparison: [
-									{
-										name: 'unplaced-at-risk',
-										direction: 'minimize',
-										before: 2,
-										after: 2,
-									},
-									{
-										name: 'preference:spring',
-										direction: 'maximize',
-										before: 1,
-										after: 0,
-									},
-								],
-								firstDecisiveComparator: 'preference:spring',
-								comparison: placementComparison,
-							},
-							{
-								status: 'chosen',
-								dates: ['2024-05-03', '2024-05-06'],
-								comparison: placementComparison,
-							},
-						],
-						deltas: [
-							{
-								kind: 'placement-added',
-								date: '2024-05-03',
-								balanceId: 'cp',
-								remainingBefore: 1,
-								remainingAfter: 0,
-								placement: plan.placements[0],
-							},
-						],
-					},
-					{
-						id: 'decision:later',
-						action: 'reject',
-						dates: ['2024-05-20'],
-						candidates: [],
-						deltas: [],
-					},
-				],
-			},
-			{
-				id: 'phase:dates',
-				name: 'dates',
-				completed: true,
-				status: 'completed',
-				decisions: [],
-			},
-		],
-		completedStages: ['obligations', 'dates'],
-	};
-}
-
 const presets = createOptimizationPresetRules();
 
 describe('CalendarYear planning outcome boundary', () => {
@@ -577,10 +403,9 @@ describe('CalendarYear planning outcome boundary', () => {
 		{ partial: false, placements: 0 },
 		{ partial: true, placements: 0 },
 	])(
-		'opens calculated statistics independently of the trace (partial: $partial, placements: $placements)',
+		'opens calculated statistics for the displayed plan (partial: $partial, placements: $placements)',
 		async ({ partial, placements }) => {
 			vi.setSystemTime(new Date('2024-05-01T12:00:00Z'));
-			const pendingTrace = deferred<PlanningTrace | undefined>();
 			const validPlan: PlanOutcome = {
 				...plan,
 				calculationDate: '2024-05-01',
@@ -632,12 +457,7 @@ describe('CalendarYear planning outcome boundary', () => {
 						reasons: [{ code: 'user-cancelled', message: 'Cancelled' }],
 					}
 				: validPlan;
-			const { calendar, calculation } = calendarFor(
+			const { calendar, calculation } = calendarFor(outcome, undefined);
-				outcome,
-				undefined,
-				undefined,
-				pendingTrace.promise,
-			);
 			await TestBed.configureTestingModule({
 				imports: [CalendarYear],
 				providers: [
@@ -693,7 +513,6 @@ describe('CalendarYear planning outcome boundary', () => {
 			expect(rules.rules).toEqual(before.rules);
 			expect(calendar.createPlanningCalculation).toHaveBeenCalledOnce();
 			expect(calculation.analyzeCounterfactual).not.toHaveBeenCalled();
-			pendingTrace.reject(new Error('Trace delivery failed'));
 			await fixture.whenStable();
 			fixture.detectChanges();
 			expect(statistics()).toEqual(expectedStatistics);
@@ -1002,14 +821,12 @@ describe('CalendarYear planning outcome boundary', () => {
 		);
 	});
 
-	it('shows the retained earnings when cancellation interrupts a different generating candidate', async () => {
+	it('shows the retained earnings after cancelling with a valid generating plan', async () => {
 		vi.setSystemTime(new Date('2024-04-28T12:00:00Z'));
-		// Flush the original trace deterministically so cancellation occurs at the observed branch.
+		// Yield between work slices so cancellation can follow a delivered valid checkpoint.
 		let elapsed = 0;
 		const clock = vi.spyOn(performance, 'now').mockImplementation(() => (elapsed += 30));
-		let checkpoint: PlanOutcome | undefined;
 		let interrupted = false;
-		let latestGenerator: string | undefined;
 		let artifacts: import('../../services/leave-planner.core').PlanningArtifacts = {};
 		try {
 			const core = await import('../../services/leave-planner.core');
@@ -1045,24 +862,11 @@ describe('CalendarYear planning outcome boundary', () => {
 							rewardType: 'other',
 						})),
 					],
-					traceProgress: (_: number, update: PlanningTraceUpdate) => {
-						if (interrupted) return;
-						for (const operation of update.operations) {
-							const deltas =
-								operation.kind === 'delta'
-									? [operation.delta]
-									: operation.kind === 'decision'
-										? (operation.decision.branch?.deltas ?? [])
-										: [];
-							for (const delta of deltas) {
-								if (delta.kind !== 'earned-activated') continue;
-								latestGenerator = delta.activation?.ruleId;
-								if (checkpoint && latestGenerator === 'before') interrupted = true;
-							}
-						}
 				},
+				(value) => {
+					if (value.ifThenContributions?.some(({ ruleId }) => ruleId === 'after'))
+						interrupted = true;
 				},
-				(value) => (checkpoint = value),
 				(value) => (artifacts = value),
 				undefined,
 				undefined,
@@ -1072,7 +876,6 @@ describe('CalendarYear planning outcome boundary', () => {
 			if (outcome.kind !== 'PlanningIncomplete' || !outcome.incumbent)
 				throw new Error('Expected a real cancellation with a retained valid plan.');
 			expect(interrupted).toBe(true);
-			expect(latestGenerator).toBe('before');
 			expect(outcome.incumbent.ifThenContributions).toMatchObject([
 				{ ruleId: 'after', earnedEntitlement: { quantity: 2, added: true } },
 			]);
@@ -1081,20 +884,7 @@ describe('CalendarYear planning outcome boundary', () => {
 				'2024-05-02',
 				'2024-05-10',
 			]);
-			const latestBranch = artifacts.trace?.phases
+			const { calendar } = calendarFor(outcome, artifacts.explanation);
-				.flatMap(({ decisions }) => decisions)
-				.filter(({ branch }) => branch)
-				.at(-1);
-			expect(latestBranch?.candidates).toMatchObject([
-				{ status: 'evaluated-rejected', dates: ['2024-04-29', '2024-04-30'] },
-			]);
-			expect(latestBranch?.branch?.deltas).toContainEqual(
-				expect.objectContaining({
-					kind: 'earned-activated',
-					activation: expect.objectContaining({ ruleId: 'before' }),
-				}),
-			);
-			const { calendar } = calendarFor(outcome, artifacts.explanation, artifacts.trace);
 			await TestBed.configureTestingModule({
 				imports: [CalendarYear],
 				providers: [
@@ -1242,12 +1032,11 @@ describe('CalendarYear planning outcome boundary', () => {
 		'replaces open statistics after %s and ignores an older valid outcome',
 		async (_, replacement: PlanningOutcome, focusMoved) => {
 			const oldOutcome = deferred<PlanningOutcome>();
-			const oldTrace = deferred<PlanningTrace | undefined>();
 			const { calendar } = calendarFor(plan);
 			calendar.createPlanningCalculation
 				.mockReturnValueOnce(calculationFor(plan))
 				.mockReturnValueOnce({
-					...calculationFor(plan, undefined, undefined, oldTrace.promise),
+					...calculationFor(plan, undefined),
 					outcome: oldOutcome.promise,
 				})
 				.mockReturnValueOnce(calculationFor(replacement));
@@ -1280,7 +1069,6 @@ describe('CalendarYear planning outcome boundary', () => {
 			fixture.detectChanges();
 			await vi.waitFor(() => expect(document.querySelector('[role="dialog"]')).toBeNull());
 			oldOutcome.resolve(plan);
-			oldTrace.resolve(jointTrace());
 			await fixture.whenStable();
 			fixture.detectChanges();
 			expect(input.planningOutcomeSignal()).toBe(replacement);
@@ -1353,7 +1141,6 @@ describe('CalendarYear planning outcome boundary', () => {
 			vi.spyOn(TestBed.inject(CalendarService), 'createPlanningCalculation').mockReturnValue({
 				...calculationFor(outcome),
 				explanation: Promise.resolve(artifacts.explanation),
-				trace: Promise.resolve(artifacts.trace),
 			});
 			const settings = TestBed.inject(CalendarSettingsService);
 			settings.setPlanningDates('2024-01-08', '2024-01-12');
@@ -1432,7 +1219,6 @@ describe('CalendarYear planning outcome boundary', () => {
 			const calculation = {
 				...calculationFor(outcome),
 				explanation: Promise.resolve(artifacts.explanation),
-				trace: Promise.resolve(artifacts.trace),
 			};
 			vi.spyOn(TestBed.inject(CalendarService), 'createPlanningCalculation').mockReturnValue(
 				calculation,
@@ -1484,7 +1270,7 @@ describe('CalendarYear planning outcome boundary', () => {
 	);
 
 	it.each([false, true])(
-		'keeps adjacent context declarations attached to the historical anchors (fixed anchor: %s)',
+		'keeps adjacent context declarations attached to displayed anchors (fixed anchor: %s)',
 		async (fixedAnchor) => {
 			const core = await import('../../services/leave-planner.core');
 			const placementDate = fixedAnchor ? '2024-07-30' : '2024-07-31';
@@ -1511,28 +1297,14 @@ describe('CalendarYear planning outcome boundary', () => {
 				undefined,
 				(value) => (artifacts = value),
 			);
-			if (outcome.kind !== 'Plan' || !artifacts.trace)
+			if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
-				throw new Error('Expected a plan and its original trace.');
-			const trace = artifacts.trace;
-			const phaseIndex = trace.phases.findIndex((phase) =>
-				phase.decisions.some((decision) =>
-					decision.deltas.some(
-						(delta) => delta.kind === 'placement-added' && delta.date === placementDate,
-					),
-				),
-			);
-			const decisionIndex = trace.phases[phaseIndex].decisions.findIndex((decision) =>
-				decision.deltas.some(
-					(delta) => delta.kind === 'placement-added' && delta.date === placementDate,
-				),
-			);
 			localStorage.setItem('leaveBalances', '[]');
 			localStorage.setItem('vacationRules', '{"version":1,"rules":[]}');
 			await TestBed.configureTestingModule({
 				imports: [CalendarYear],
 				providers: [provideZonelessChangeDetection()],
 			}).compileComponents();
-			const calculation = calculationFor(outcome, artifacts.explanation, trace);
+			const calculation = calculationFor(outcome, artifacts.explanation);
 			vi.spyOn(TestBed.inject(CalendarService), 'createPlanningCalculation').mockReturnValue(
 				calculation,
 			);
@@ -1543,29 +1315,10 @@ describe('CalendarYear planning outcome boundary', () => {
 			await fixture.whenStable();
 			fixture.detectChanges();
 			const root: HTMLElement = fixture.nativeElement;
-			activateWithKeyboard(root.querySelector<HTMLElement>('.trace-explorer summary')!);
 			fixture.detectChanges();
 			await fixture.whenStable();
 			await new Promise<void>((resolve) => setTimeout(resolve, 0));
 			fixture.detectChanges();
-			activateWithKeyboard(
-				root.querySelectorAll<HTMLElement>('.trace-phases > button')[phaseIndex],
-			);
-			fixture.detectChanges();
-			for (let index = 0; index < decisionIndex; index++) {
-				activateWithKeyboard(
-					root.querySelector<HTMLElement>('[aria-label="Next decision"]')!,
-				);
-				fixture.detectChanges();
-			}
-			activateWithKeyboard(root.querySelector<HTMLElement>('.trace-toolbar button')!);
-			fixture.detectChanges();
-			const before = root.querySelector<HTMLButtonElement>('button[data-date="2024-08-01"]');
-			if (fixedAnchor) {
-				expect(before?.classList).toContain('selected');
-				expect(before?.classList).toContain('cp');
-			} else expect(before).toBeNull();
-			activateWithKeyboard(root.querySelectorAll<HTMLElement>('.trace-toolbar button')[1]);
 			fixture.detectChanges();
 			const after = root.querySelector<HTMLButtonElement>('button[data-date="2024-08-01"]')!;
 			expect(after.classList).toContain('selected');
@@ -1573,7 +1326,7 @@ describe('CalendarYear planning outcome boundary', () => {
 			expect(after.classList).toContain('context-only');
 			expect(after.disabled).toBe(true);
 			expect(after.getAttribute('aria-label')).toContain('Already booked');
-			expect(fixture.componentInstance['traceState']()?.placements).toEqual(
+			expect(fixture.componentInstance['displayedPlan']()?.placements).toEqual(
 				outcome.placements,
 			);
 			TestBed.inject(UserInputService).toggleDeclaredDay('2024-08-01', 'rtt');
@@ -1871,11 +1624,9 @@ describe('CalendarYear planning outcome boundary', () => {
 			],
 		};
 		const lateExplanation = deferred<PlanningExplanation | undefined>();
-		const lateTrace = deferred<PlanningTrace | undefined>();
 		const initialCalculation = {
 			...calculationFor(initial, oldExplanation),
 			explanation: lateExplanation.promise,
-			trace: lateTrace.promise,
 		};
 		const rule = {
 			id: 'linked',
@@ -1946,26 +1697,10 @@ describe('CalendarYear planning outcome boundary', () => {
 			horizon: submitted.horizon,
 			declaredDays: submitted.declaredDays,
 		});
-		const originalTrace: PlanningTrace = {
-			status: 'ready',
-			initialState: {
-				horizon: initial.horizon,
-				declaredDays: initial.declaredDays,
-				balances: [],
-				placements: [],
-				earnedActivations: [],
-			},
-			phases: [],
-			completedStages: initial.completedStages,
-		};
 		lateExplanation.resolve(oldExplanation);
-		lateTrace.resolve(originalTrace);
 		await fixture.whenStable();
 		await new Promise<void>((resolve) => setTimeout(resolve, 0));
 		fixture.detectChanges();
-		expect(fixture.componentInstance['planningTrace']()).toBe(originalTrace);
-		expect(fixture.componentInstance['traceLoading']()).toBe(false);
-		expect(fixture.componentInstance['traceResolved']()).toBe(true);
 		const details = root.querySelector<HTMLDetailsElement>('.plan-details')!;
 		details.open = true;
 		details.dispatchEvent(new Event('toggle'));
@@ -1986,19 +1721,14 @@ describe('CalendarYear planning outcome boundary', () => {
 		expect(input.declaredDaysSignal()).toEqual([{ date: '2024-05-10', type: 'other' }]);
 	});
 
-	it('calibrates the wait through calendar rendering while a long trace remains pending', async () => {
+	it('calibrates the wait through calendar rendering independently of explanation delivery', async () => {
 		let now = 1_000;
 		const clock = vi.spyOn(performance, 'now').mockImplementation(() => now);
 		try {
 			localStorage.setItem('vacationRules', '{"version":1,"rules":[]}');
 			const pending = deferred<PlanningOutcome>();
-			const trace = deferred<PlanningTrace | undefined>();
+			const delayedExplanation = deferred<PlanningExplanation | undefined>();
-			const { calendar, calculation } = calendarFor(
+			const { calendar, calculation } = calendarFor(plan, undefined);
-				plan,
-				undefined,
-				undefined,
-				trace.promise,
-			);
 			await TestBed.configureTestingModule({
 				imports: [CalendarYear],
 				providers: [
@@ -2021,6 +1751,7 @@ describe('CalendarYear planning outcome boundary', () => {
 			calendar.createPlanningCalculation.mockReturnValue({
 				...calculation,
 				outcome: pending.promise,
+				explanation: delayedExplanation.promise,
 				snapshot: { ...calculation.snapshot, ...submitted },
 			});
 			const fixture = TestBed.createComponent(CalendarYear);
@@ -2036,11 +1767,13 @@ describe('CalendarYear planning outcome boundary', () => {
 			expect(fixture.nativeElement.querySelector('.loading-overlay')).toBeNull();
 			expect(fixture.nativeElement.querySelectorAll('button.selected')).toHaveLength(2);
 			expect(duration.estimate()).toEqual({ minimum: 10, maximum: 60, unit: 'seconds' });
+			expect(fixture.componentInstance['planningExplanation']()).toBeNull();
 			now = 321_000;
-			trace.reject(new Error('Late trace delivery failed'));
+			delayedExplanation.resolve(explanation);
 			await fixture.whenStable();
 			await new Promise<void>((resolve) => setTimeout(resolve, 0));
 			fixture.detectChanges();
+			expect(fixture.componentInstance['planningExplanation']()).toBe(explanation);
 			expect(duration.estimate()).toEqual({ minimum: 10, maximum: 60, unit: 'seconds' });
 			expect(fixture.nativeElement.querySelectorAll('button.selected')).toHaveLength(2);
 			expect(calendar.createPlanningCalculation).toHaveBeenCalledOnce();
@@ -2176,19 +1909,13 @@ describe('CalendarYear planning outcome boundary', () => {
 		'cancels accessibly with a valid incumbent: %s, then allows a new calculation',
 		async (withIncumbent) => {
 			const pending = deferred<PlanningOutcome>();
-			const delayedTrace = deferred<PlanningTrace | undefined>();
 			const cancelled: PlanningIncompleteOutcome = {
 				kind: 'PlanningIncomplete',
 				incumbent: withIncumbent ? plan : undefined,
 				completedStages: ['validation'],
 				reasons: [{ code: 'user-cancelled', message: 'The calculation was cancelled.' }],
 			};
-			const { calendar, calculation } = calendarFor(
+			const { calendar, calculation } = calendarFor(cancelled, undefined);
-				cancelled,
-				undefined,
-				undefined,
-				delayedTrace.promise,
-			);
 			calendar.createPlanningCalculation
 				.mockReturnValueOnce({ ...calculation, outcome: pending.promise })
 				.mockReturnValueOnce(calculationFor(plan, explanation));
@@ -2226,7 +1953,6 @@ describe('CalendarYear planning outcome boundary', () => {
 			fixture.detectChanges();
 			expect(calendar.createPlanningCalculation).toHaveBeenCalledTimes(2);
 			expect(root.querySelectorAll('button.selected')).toHaveLength(2);
-			delayedTrace.resolve({ ...jointTrace(), status: 'incomplete' });
 			await fixture.whenStable();
 			expect(root.querySelectorAll('button.selected')).toHaveLength(2);
 		},
@@ -2304,14 +2030,13 @@ describe('CalendarYear planning outcome boundary', () => {
 		},
 	);
 
-	it('ignores an older outcome, explanation and trace after a new horizon is submitted', async () => {
+	it('ignores an older outcome and explanation after a new horizon is submitted', async () => {
 		await TestBed.configureTestingModule({
 			imports: [CalendarYear],
 			providers: [provideZonelessChangeDetection()],
 		}).compileComponents();
 		const oldOutcome = deferred<PlanningOutcome>();
 		const oldExplanation = deferred<PlanningExplanation | undefined>();
-		const oldTrace = deferred<PlanningTrace | undefined>();
 		const calendar = TestBed.inject(CalendarService);
 		const calculate = vi
 			.spyOn(calendar, 'createPlanningCalculation')
@@ -2319,7 +2044,6 @@ describe('CalendarYear planning outcome boundary', () => {
 				...calculationFor(plan),
 				outcome: oldOutcome.promise,
 				explanation: oldExplanation.promise,
-				trace: oldTrace.promise,
 			})
 			.mockReturnValueOnce(calculationFor(conflict));
 		const settings = TestBed.inject(CalendarSettingsService);
@@ -2332,14 +2056,12 @@ describe('CalendarYear planning outcome boundary', () => {
 		await fixture.whenStable();
 		oldOutcome.resolve(plan);
 		oldExplanation.resolve(explanation);
-		oldTrace.resolve(jointTrace());
 		await fixture.whenStable();
 		await new Promise<void>((resolve) => setTimeout(resolve, 0));
 		fixture.detectChanges();
 		expect(calculate).toHaveBeenCalledTimes(2);
 		expect(fixture.componentInstance['planningOutcome']()).toBe(conflict);
 		expect(fixture.componentInstance['planningExplanation']()).toBeNull();
-		expect(fixture.componentInstance['planningTrace']()).toBeNull();
 		expect(fixture.componentInstance['planningHorizon']()).toEqual({
 			start: '2021-05-14',
 			end: '2021-05-15',
@@ -2636,9 +2358,7 @@ describe('CalendarYear planning outcome boundary', () => {
 
 		const root = fixture.nativeElement as HTMLElement;
 		const planDetails = root.querySelector<HTMLDetailsElement>('.plan-details')!;
-		const traceDetails = root.querySelector<HTMLDetailsElement>('.trace-explorer')!;
 		expect(planDetails.open).toBe(false);
-		expect(traceDetails.open).toBe(false);
 		activateWithKeyboard(planDetails.querySelector<HTMLElement>('summary')!);
 		await new Promise<void>((resolve) => setTimeout(resolve, 0));
 		fixture.detectChanges();
@@ -3128,108 +2848,6 @@ describe('CalendarYear planning outcome boundary', () => {
 		await vi.waitFor(() => expect(document.querySelector('[role="dialog"]')).toBeNull());
 	});
 
-	it('announces trace loading and completion while keeping the completed plan available', async () => {
-		const outcomeDelivery = deferred<PlanningOutcome>();
-		const traceDelivery = deferred<PlanningTrace | undefined>();
-		const { calendar, calculation } = calendarFor(
-			plan,
-			explanation,
-			undefined,
-			traceDelivery.promise,
-		);
-		calendar.createPlanningCalculation.mockReturnValue({
-			...calculation,
-			outcome: outcomeDelivery.promise,
-		});
-		await TestBed.configureTestingModule({
-			imports: [CalendarYear],
-			providers: [
-				provideZonelessChangeDetection(),
-				{ provide: CalendarService, useValue: calendar },
-			],
-		}).compileComponents();
-		TestBed.inject(TranslationService).setLanguage('en');
-		const fixture = TestBed.createComponent(CalendarYear);
-		fixture.detectChanges();
-		await fixture.whenStable();
-		await new Promise<void>((resolve) => setTimeout(resolve, 0));
-		fixture.detectChanges();
-
-		const root = fixture.nativeElement as HTMLElement;
-		expect(root.querySelector('.loading-overlay')).not.toBeNull();
-		expect(root.querySelectorAll('button.selected')).toHaveLength(0);
-		expect(calendar.selectedDatesForPlan).not.toHaveBeenCalled();
-		expect(root.querySelector('.cancel-calculation')).not.toBeNull();
-		outcomeDelivery.resolve(plan);
-		await fixture.whenStable();
-		await new Promise<void>((resolve) => setTimeout(resolve, 0));
-		fixture.detectChanges();
-		const plannedButtons = Array.from(root.querySelectorAll('button.selected'));
-		expect(plannedButtons).toHaveLength(2);
-		expect(root.querySelector('.loading-overlay')).toBeNull();
-		const liveMessage = root.querySelector<HTMLElement>('.calendar-year > p[aria-live]')!;
-		const traceDetails = root.querySelector<HTMLDetailsElement>('.trace-explorer')!;
-		activateWithKeyboard(traceDetails.querySelector('summary')!, ' ');
-		fixture.detectChanges();
-		expect(traceDetails.querySelector('[role="status"]')?.textContent).toContain(
-			'decision trace is still loading',
-		);
-		expect(liveMessage.getAttribute('aria-atomic')).toBe('true');
-		expect(root.querySelector('.plan-summary')).not.toBeNull();
-
-		traceDelivery.resolve(jointTrace());
-		await fixture.whenStable();
-		fixture.detectChanges();
-		expect(liveMessage.textContent).toContain('decision trace has loaded');
-		expect(Array.from(root.querySelectorAll('button.selected'))).toEqual(plannedButtons);
-		expect(calendar.createPlanningCalculation).toHaveBeenCalledOnce();
-		expect(calendar.selectedDatesForPlan).toHaveBeenCalledOnce();
-		await vi.waitFor(() => expect(traceDetails.querySelector('[role="status"]')).toBeNull());
-		root.querySelector<HTMLButtonElement>(
-			'.trace-decisions nav button[aria-label="Next decision"]',
-		)!.click();
-		fixture.detectChanges();
-		expect(root.querySelector('.candidate-list details')).not.toBeNull();
-	});
-
-	it('announces trace delivery failure without discarding the completed plan', async () => {
-		const traceDelivery = deferred<PlanningTrace | undefined>();
-		const { calendar } = calendarFor(plan, explanation, undefined, traceDelivery.promise);
-		await TestBed.configureTestingModule({
-			imports: [CalendarYear],
-			providers: [
-				provideZonelessChangeDetection(),
-				{ provide: CalendarService, useValue: calendar },
-			],
-		}).compileComponents();
-		TestBed.inject(TranslationService).setLanguage('en');
-		const fixture = TestBed.createComponent(CalendarYear);
-		fixture.detectChanges();
-		await fixture.whenStable();
-		await new Promise<void>((resolve) => setTimeout(resolve, 0));
-		fixture.detectChanges();
-		const root = fixture.nativeElement as HTMLElement;
-		const traceDetails = root.querySelector<HTMLDetailsElement>('.trace-explorer')!;
-		activateWithKeyboard(traceDetails.querySelector('summary')!, ' ');
-		fixture.detectChanges();
-		await new Promise<void>((resolve) => setTimeout(resolve, 0));
-		fixture.detectChanges();
-		traceDelivery.reject(new Error('trace transfer failed'));
-		await vi.waitFor(() => {
-			fixture.detectChanges();
-			expect(root.querySelector('.calendar-year > p[aria-live]')?.textContent).toContain(
-				'No decision trace is available',
-			);
-		});
-		expect(root.querySelector('.calendar-year > p[aria-live]')?.textContent).toContain(
-			'No decision trace is available',
-		);
-		expect(traceDetails.querySelector('[role="alert"]')?.textContent).toContain(
-			'trace transfer failed',
-		);
-		expect(root.querySelector('.plan-summary')).not.toBeNull();
-	});
-
 	it('announces an explicit comparison failure and retries inside the dialog', async () => {
 		const { calendar, calculation } = calendarFor(plan, explanation);
 		const firstAttempt = deferred<CounterfactualAnalysis>();
@@ -3304,13 +2922,13 @@ describe('CalendarYear planning outcome boundary', () => {
 		expect(document.activeElement).toBe(focusedBeforeResult);
 	});
 
-	it('renders conflict causes and replays an atomic trace decision', async () => {
+	it('renders conflict causes with their reported obligations', async () => {
 		const conflictExplanation: PlanningExplanation = {
 			kind: 'ConflictExplanation',
 			conflictingRules: [{ id: 'rule', label: 'Required spring leave' }],
 			bottleneck: { code: 'typed-capacity', message: 'No CP entitlement is available.' },
 		};
-		let setup = calendarFor(conflict, conflictExplanation);
+		const setup = calendarFor(conflict, conflictExplanation);
 		await TestBed.configureTestingModule({
 			imports: [CalendarYear],
 			providers: [
@@ -3319,7 +2937,7 @@ describe('CalendarYear planning outcome boundary', () => {
 			],
 		}).compileComponents();
 		TestBed.inject(TranslationService).setLanguage('en');
-		let fixture = TestBed.createComponent(CalendarYear);
+		const fixture = TestBed.createComponent(CalendarYear);
 		fixture.detectChanges();
 		await fixture.whenStable();
 		await new Promise<void>((resolve) => setTimeout(resolve, 0));
@@ -3330,208 +2948,6 @@ describe('CalendarYear planning outcome boundary', () => {
 		expect(fixture.nativeElement.querySelector('.conflict-explanation').textContent).toContain(
 			'No CP entitlement is available.',
 		);
-
-		TestBed.resetTestingModule();
-		const trace = jointTrace();
-		setup = calendarFor(plan, explanation, trace);
-		vi.mocked(setup.calculation.historicalEligibility).mockResolvedValue([
-			{
-				date: '2024-01-02',
-				reason: {
-					code: 'unavailable',
-					message: 'This balance is not available until January 4.',
-				},
-			},
-			{
-				date: '2024-01-08',
-				reason: { code: 'expired', message: 'This balance expired on January 7.' },
-			},
-		]);
-		const eligibilityRetry = deferred<readonly HistoricalEligibilityReason[]>();
-		vi.mocked(setup.calculation.historicalEligibility)
-			.mockRejectedValueOnce(new Error('Historical eligibility unavailable.'))
-			.mockImplementationOnce(() => eligibilityRetry.promise);
-		setup.calendar.selectedDatesForPlan.mockImplementation((value) =>
-			selectedDatesForPlan(value, true),
-		);
-		await TestBed.configureTestingModule({
-			imports: [CalendarYear],
-			providers: [
-				provideZonelessChangeDetection(),
-				{ provide: CalendarService, useValue: setup.calendar },
-			],
-		}).compileComponents();
-		TestBed.inject(TranslationService).setLanguage('en');
-		fixture = TestBed.createComponent(CalendarYear);
-		fixture.detectChanges();
-		await fixture.whenStable();
-		await new Promise<void>((resolve) => setTimeout(resolve, 0));
-		fixture.detectChanges();
-		const root = fixture.nativeElement as HTMLElement;
-		const traceDetails = root.querySelector<HTMLDetailsElement>('.trace-explorer')!;
-		activateWithKeyboard(traceDetails.querySelector('summary')!, ' ');
-		fixture.detectChanges();
-		await fixture.whenStable();
-		await new Promise<void>((resolve) => setTimeout(resolve, 0));
-		fixture.detectChanges();
-		expect(traceDetails.open).toBe(true);
-		const nextDecision = root.querySelector<HTMLButtonElement>(
-			'.trace-decisions nav button[aria-label="Next decision"]',
-		)!;
-		activateWithKeyboard(nextDecision);
-		await vi.waitFor(() => {
-			expect(fixture.componentInstance['historicalEligibilityError']()).toBe(
-				'Historical eligibility unavailable.',
-			);
-		});
-		fixture.detectChanges();
-		expect(fixture.componentInstance['traceReplay']()).toBe(true);
-		expect(root.querySelector('[role="alert"]')?.textContent).toContain(
-			'Historical eligibility unavailable.',
-		);
-		expect(root.querySelector('.sr-only[role="status"]')?.textContent).toContain(
-			'Original date eligibility could not be checked.',
-		);
-		const retryEligibility = Array.from(root.querySelectorAll('button')).find((button) =>
-			button.textContent?.includes('Retry date eligibility check'),
-		)!;
-		activateWithKeyboard(retryEligibility);
-		fixture.detectChanges();
-		expect(root.querySelector('[role="status"]')?.textContent).toContain(
-			'Checking which dates this leave could use',
-		);
-		eligibilityRetry.resolve([
-			{
-				date: '2024-01-02',
-				reason: {
-					code: 'unavailable',
-					message: 'This balance is not available until January 4.',
-				},
-			},
-			{
-				date: '2024-01-08',
-				reason: { code: 'expired', message: 'This balance expired on January 7.' },
-			},
-		]);
-		await vi.waitFor(() => {
-			expect([...fixture.componentInstance['historicalIneligibility']().keys()]).toEqual([
-				'2024-01-02',
-				'2024-01-08',
-			]);
-		});
-		fixture.detectChanges();
-		expect(setup.calculation.historicalEligibility).toHaveBeenCalledWith({
-			decisionId: 'decision:joint',
-			placement: plan.placements[0],
-		});
-		expect(fixture.componentInstance['traceReplay']()).toBe(true);
-		expect(fixture.componentInstance['historicalEligibilityError']()).toBeNull();
-		expect([...fixture.componentInstance['historicalIneligibility']().keys()]).toEqual([
-			'2024-01-02',
-			'2024-01-08',
-		]);
-		const historicalAvailability = fixture.componentInstance['dateStatuses']();
-		expect(historicalAvailability['2024-01-02']).toMatchObject({
-			kind: 'ineligible',
-			reason: 'This leave balance cannot be used on this date.',
-		});
-		expect(historicalAvailability['2024-01-08']).toMatchObject({
-			kind: 'ineligible',
-			reason: 'This date is after the leave balance expires.',
-		});
-		let earnedBalance = Array.from(root.querySelectorAll('.trace-state-balance')).find((item) =>
-			item.textContent?.includes('earned:spring:2024'),
-		)!;
-		expect(earnedBalance.textContent).toContain('Available from 4 May 2024');
-		expect(earnedBalance.textContent).toContain('Expires on 4 May 2025');
-		const jointAfterButton =
-			root.querySelectorAll<HTMLButtonElement>('.trace-toolbar button')[1]!;
-		activateWithKeyboard(jointAfterButton);
-		fixture.detectChanges();
-		earnedBalance = Array.from(root.querySelectorAll('.trace-state-balance')).find((item) =>
-			item.textContent?.includes('earned:spring:2024'),
-		)!;
-		expect(earnedBalance.textContent).toContain('Available from 7 May 2024');
-		expect(earnedBalance.textContent).toContain('Expires on 7 May 2025');
-		expect(
-			root
-				.querySelector('.trace-decisions output[aria-current="step"]')
-				?.getAttribute('aria-label'),
-		).toContain('2024-05-03, 2024-05-06');
-		const candidates = Array.from(
-			root.querySelectorAll<HTMLDetailsElement>('.candidate-list > details'),
-		);
-		expect(candidates).toHaveLength(2);
-		expect(candidates[0].querySelector('summary')?.textContent).toContain(
-			'2024-05-10, 2024-05-13',
-		);
-		expect(candidates[1].querySelector('summary')?.textContent).toContain(
-			'2024-05-03, 2024-05-06',
-		);
-		expect(candidates.every((candidate) => !candidate.open)).toBe(true);
-		const technicalComparison = candidates[0].querySelector('.technical-comparison')!;
-		expect(technicalComparison.closest('details')).toBe(candidates[0]);
-		expect(candidates[0].open).toBe(false);
-		activateWithKeyboard(candidates[0].querySelector('summary')!, 'Enter');
-		fixture.detectChanges();
-		expect(candidates[0].open).toBe(true);
-		expect(candidates[0].textContent).toContain(
-			'This branch cannot satisfy both required dates.',
-		);
-		expect(technicalComparison.textContent).toContain('Actual stage comparison');
-		const traceImpact = candidates[0].querySelector('.criteria-detail')!;
-		expect(traceImpact.textContent).toContain('Full-plan effect of this branch');
-		expect(traceImpact.querySelectorAll('.decisive-row')).toHaveLength(0);
-		expect(traceImpact.textContent).not.toContain('First difference');
-		const decisiveComparator = candidates[0].querySelector(
-			'.technical-comparison tbody tr.decisive-row',
-		)!;
-		expect(decisiveComparator.textContent).toContain('preference:spring');
-		expect(decisiveComparator.textContent).toContain('1');
-		expect(decisiveComparator.textContent).toContain('0');
-		expect(
-			candidates[0].textContent!.indexOf('This branch cannot satisfy both required dates.'),
-		).toBeLessThan(candidates[0].textContent!.indexOf('preference:spring'));
-		expect(document.activeElement).toBe(candidates[0].querySelector('summary'));
-
-		const beforeButton = root.querySelector('.trace-toolbar button') as HTMLButtonElement;
-		const afterButton = root.querySelectorAll('.trace-toolbar button')[1] as HTMLButtonElement;
-		activateWithKeyboard(beforeButton, ' ');
-		fixture.detectChanges();
-		expect(beforeButton.getAttribute('aria-pressed')).toBe('true');
-		expect(root.querySelector('.trace-state-summary')?.textContent).toContain(
-			'1 earned activations',
-		);
-		expect(root.querySelector('.trace-state-summary')?.textContent).toContain(
-			'cp: 1 remaining',
-		);
-		expect(root.querySelector('.trace-state-summary')?.textContent).toContain('1 placements');
-		activateWithKeyboard(root.querySelector<HTMLButtonElement>('.statistics-button')!);
-		await fixture.whenStable();
-		expect(
-			Array.from(document.querySelectorAll('[role="dialog"] dd'), (value) =>
-				value.textContent?.trim(),
-			),
-		).toEqual(['2', '4', '6', '6', '—', '—', '0', '0']);
-		document.querySelector<HTMLButtonElement>('[role="dialog"] button')!.click();
-		await vi.waitFor(() => expect(document.querySelector('[role="dialog"]')).toBeNull());
-		activateWithKeyboard(afterButton);
-		fixture.detectChanges();
-		expect(afterButton.getAttribute('aria-pressed')).toBe('true');
-		expect(root.querySelector('.trace-state-summary')?.textContent).toContain('2 placements');
-		expect(root.querySelector('.trace-state-summary')?.textContent).toContain(
-			'1 earned activations',
-		);
-		expect(root.querySelector('.trace-state-summary')?.textContent).toContain(
-			'cp: 0 remaining',
-		);
-		const weekend = root.querySelector<HTMLButtonElement>('button[data-date="2024-05-04"]')!;
-		expect(weekend.getAttribute('aria-label')).toContain('Ineligible');
-		expect(weekend.querySelector('.status-marker')?.textContent).toBe('×');
-		const legend = root.querySelector('.calendar-legend')?.textContent ?? '';
-		expect(legend).toContain('Evaluated and rejected');
-		expect(legend).toContain('Not examined');
-		expect(root.querySelector('.counterfactual-result')).toBeNull();
 	});
 
 	it('turns planner rejection into an incomplete error and clears loading', async () => {

src/app/components/calendar-year/calendar-year.html

@@ -533,476 +533,8 @@
 				{{ tr().planning.explanationError }} {{ explanationError()!.message }}
 			</p>
 		}
-
-		@if (planningOutcome() && planningOutcome()?.kind !== 'InvalidInput') {
-			<details class="trace-explorer" [open]="traceOpen()" (toggle)="toggleTrace($event)">
-				<summary>
-					<mat-icon aria-hidden="true">account_tree</mat-icon>
-					<span
-						>{{ tr().planning.traceTitle
-						}}<small>{{ tr().planning.traceHelp }}</small></span
-					>
-					<mat-icon class="disclosure-chevron" aria-hidden="true">expand_more</mat-icon>
-				</summary>
-				@if (traceLoading()) {
-					<p role="status">{{ tr().planning.traceLoading }}</p>
-				} @else if (planningTrace(); as trace) {
-					@if (trace.error) {
-						<p class="inline-error" role="alert">{{ trace.error.message }}</p>
-					}
-					<div class="trace-layout">
-						<nav class="trace-phases" [attr.aria-label]="tr().planning.phases">
-							<div class="trace-phase-stepper">
-								<button
-									type="button"
-									data-phase-step="first"
-									[attr.aria-disabled]="tracePhaseIndex() === 0"
-									[attr.aria-label]="tr().planning.firstPhase"
-									(click)="stepTracePhase('first')"
-								>
-									<mat-icon aria-hidden="true">first_page</mat-icon>
-								</button>
-								<button
-									type="button"
-									data-phase-step="previous"
-									[attr.aria-disabled]="tracePhaseIndex() === 0"
-									[attr.aria-label]="tr().planning.previousPhase"
-									(click)="stepTracePhase('previous')"
-								>
-									<mat-icon aria-hidden="true">chevron_left</mat-icon>
-								</button>
-								<output
-									aria-current="step"
-									[attr.aria-label]="tracePhaseAnnouncement()"
-									>{{ tracePhaseIndex() + 1 }} {{ tr().planning.of }}
-									{{ trace.phases.length }}</output
-								>
-								<button
-									type="button"
-									data-phase-step="next"
-									[attr.aria-disabled]="
-										tracePhaseIndex() === trace.phases.length - 1
-									"
-									[attr.aria-label]="tr().planning.nextPhase"
-									(click)="stepTracePhase('next')"
-								>
-									<mat-icon aria-hidden="true">chevron_right</mat-icon>
-								</button>
-								<button
-									type="button"
-									data-phase-step="last"
-									[attr.aria-disabled]="
-										tracePhaseIndex() === trace.phases.length - 1
-									"
-									[attr.aria-label]="tr().planning.lastPhase"
-									(click)="stepTracePhase('last')"
-								>
-									<mat-icon aria-hidden="true">last_page</mat-icon>
-								</button>
-							</div>
-							@for (phase of trace.phases; track phase.id; let index = $index) {
-								<button
-									type="button"
-									[class.active]="index === tracePhaseIndex()"
-									[attr.aria-pressed]="index === tracePhaseIndex()"
-									(click)="selectTracePhase(index)"
-								>
-									<span>{{ phaseLabel(phase.name) }}</span>
-									<small>{{ tracePhaseStatusLabel(phase.status) }}</small>
-								</button>
-							}
-						</nav>
-
-						@if (selectedTracePhase(); as phase) {
-							<section class="trace-decisions" aria-labelledby="trace-phase-title">
-								<h3 id="trace-phase-title">{{ phaseLabel(phase.name) }}</h3>
-								@if (phase.decisions.length) {
-									<nav [attr.aria-label]="tr().planning.decisions">
-										<button
-											type="button"
-											[attr.aria-disabled]="traceDecisionIndex() === 0"
-											[attr.aria-label]="tr().planning.firstDecision"
-											(click)="stepTraceDecision('first')"
-										>
-											<mat-icon aria-hidden="true">first_page</mat-icon>
-										</button>
-										<button
-											type="button"
-											[attr.aria-disabled]="traceDecisionIndex() === 0"
-											[attr.aria-label]="tr().planning.previousDecision"
-											(click)="stepTraceDecision('previous')"
-										>
-											<mat-icon aria-hidden="true">chevron_left</mat-icon>
-										</button>
-										<output
-											aria-current="step"
-											[attr.aria-label]="traceDecisionAnnouncement()"
-											>{{ tr().planning.decision }}
-											{{ traceDecisionIndex() + 1 }} {{ tr().planning.of }}
-											{{ phase.decisions.length }}</output
-										>
-										<button
-											type="button"
-											[attr.aria-disabled]="
-												traceDecisionIndex() === phase.decisions.length - 1
-											"
-											[attr.aria-label]="tr().planning.nextDecision"
-											(click)="stepTraceDecision('next')"
-										>
-											<mat-icon aria-hidden="true">chevron_right</mat-icon>
-										</button>
-										<button
-											type="button"
-											[attr.aria-disabled]="
-												traceDecisionIndex() === phase.decisions.length - 1
-											"
-											[attr.aria-label]="tr().planning.lastDecision"
-											(click)="stepTraceDecision('last')"
-										>
-											<mat-icon aria-hidden="true">last_page</mat-icon>
-										</button>
-									</nav>
-
-									@if (selectedTraceDecision(); as decision) {
-										<div
-											class="trace-toolbar"
-											role="group"
-											[attr.aria-label]="tr().planning.replay"
-										>
-											<button
-												type="button"
-												[attr.aria-pressed]="
-													traceReplay() && traceMoment() === 'before'
-												"
-												(click)="showTraceMoment('before')"
-											>
-												{{ tr().planning.before }}
-											</button>
-											<button
-												type="button"
-												[attr.aria-pressed]="
-													traceReplay() && traceMoment() === 'after'
-												"
-												(click)="showTraceMoment('after')"
-											>
-												{{ tr().planning.after }}
-											</button>
-											<button
-												type="button"
-												[attr.aria-pressed]="!traceReplay()"
-												(click)="showFinalPlan()"
-											>
-												{{ tr().planning.finalPlan }}
-											</button>
-										</div>
-										@if (historicalEligibilityLoading()) {
-											<p role="status">
-												{{ tr().planning.historicalEligibilityLoading }}
-											</p>
-										}
-										@if (historicalEligibilityError(); as error) {
-											<p role="alert">
-												{{ tr().planning.historicalEligibilityError }}
-												{{ error }}
-												<button
-													type="button"
-													(click)="retryHistoricalEligibility()"
-												>
-													{{ tr().planning.retryHistoricalEligibility }}
-												</button>
-											</p>
-										}
-										<p>
-											<strong>{{ tr().planning.dates }}:</strong>
-											{{
-												decision.dates.length
-													? decision.dates.join(', ')
-													: tr().planning.none
-											}}
-										</p>
-										@if (decision.reason) {
-											<p>
-												<strong>{{ tr().planning.reason }}:</strong>
-												{{ decision.reason.message }}
-											</p>
-										}
-
-										<h4>{{ tr().planning.candidates }}</h4>
-										@if (decision.candidates.length > 50) {
-											<nav
-												class="candidate-pagination"
-												[attr.aria-label]="tr().planning.candidates"
-											>
-												<button
-													type="button"
-													[attr.aria-disabled]="
-														traceCandidatePage() === 0
-													"
-													[attr.aria-label]="
-														tr().planning.previousCandidates
-													"
-													(click)="stepTraceCandidatePage(-1)"
-												>
-													<mat-icon aria-hidden="true"
-														>chevron_left</mat-icon
-													>
-												</button>
-												<output
-													>{{ tr().planning.page }}
-													{{ traceCandidatePage() + 1 }}
-													{{ tr().planning.of }}
-													{{ traceCandidatePages() }}</output
-												>
-												<button
-													type="button"
-													[attr.aria-disabled]="
-														traceCandidatePage() ===
-														traceCandidatePages() - 1
-													"
-													[attr.aria-label]="tr().planning.nextCandidates"
-													(click)="stepTraceCandidatePage(1)"
-												>
-													<mat-icon aria-hidden="true"
-														>chevron_right</mat-icon
-													>
-												</button>
-											</nav>
-										}
-										<div class="candidate-list">
-											@for (
-												candidate of visibleTraceCandidates();
-												track $index
-											) {
-												<details>
-													<summary>
-														<span
-															class="status-symbol"
-															aria-hidden="true"
-															>{{
-																candidate.status === 'chosen'
-																	? '✓'
-																	: candidate.status ===
-																		  'ineligible'
-																		? '×'
-																		: '•'
-															}}</span
-														>
-														{{ traceStatusLabel(candidate.status) }} ·
-														@if (
-															candidate.sourceDate &&
-															candidate.sourceDate !== candidate.date
-														) {
-															{{ candidate.sourceDate }} →
-														}
-														{{
-															candidate.dates?.join(', ') ||
-																candidate.date ||
-																tr().planning.none
-														}}
-													</summary>
-													@if (candidate.reason) {
-														<p>{{ candidate.reason.message }}</p>
-													}
-													@if (candidate.technicalComparison?.length) {
-														<section class="technical-comparison">
-															<h5>
-																{{
-																	tr().planning.details
-																		.traceStageTitle
-																}}
-															</h5>
-															<p class="calculation-intro">
-																{{
-																	tr().planning.details
-																		.traceStageHelp
-																}}
-															</p>
-															<table class="impact-table">
-																<thead>
-																	<tr>
-																		<th scope="col">
-																			{{
-																				tr().planning
-																					.explanation
-																					.criterion
-																			}}
-																		</th>
-																		<th scope="col">
-																			{{
-																				tr().planning.before
-																			}}
-																		</th>
-																		<th scope="col">
-																			{{
-																				tr().planning.after
-																			}}
-																		</th>
-																	</tr>
-																</thead>
-																<tbody>
-																	@for (
-																		comparator of candidate.technicalComparison;
-																		track $index
-																	) {
-																		<tr
-																			[class.decisive-row]="
-																				comparator.name ===
-																				candidate.firstDecisiveComparator
-																			"
-																		>
-																			<th scope="row">
-																				<code>{{
-																					comparator.name
-																				}}</code>
-																				<small>{{
-																					comparator.direction ===
-																					'maximize'
-																						? tr()
-																								.planning
-																								.details
-																								.higher
-																						: tr()
-																								.planning
-																								.details
-																								.lower
-																				}}</small>
-																				@if (
-																					comparator.name ===
-																					candidate.firstDecisiveComparator
-																				) {
-																					<span
-																						class="decisive-label"
-																						>{{
-																							tr()
-																								.planning
-																								.details
-																								.firstDifference
-																						}}</span
-																					>
-																				}
-																			</th>
-																			<td>
-																				{{
-																					comparator.before
-																				}}
-																			</td>
-																			<td>
-																				{{
-																					comparator.after
-																				}}
-																			</td>
-																		</tr>
-																	}
-																</tbody>
-															</table>
-														</section>
-													}
-													@if (candidate.comparison; as comparison) {
-														<div class="calculation-content">
-															<ng-container
-																[ngTemplateOutlet]="
-																	calculationTable
-																"
-																[ngTemplateOutletContext]="{
-																	comparison,
-																	beforeLabel:
-																		tr().planning.before,
-																	afterLabel: tr().planning.after,
-																	audit: comparison,
-																	traceEffect:
-																		!!candidate
-																			.technicalComparison
-																			?.length,
-																}"
-															/>
-														</div>
-													}
-													@if (candidate.placement) {
-														<button
-															type="button"
-															(click)="
-																analyzeTraceCandidate(candidate)
-															"
-														>
-															{{ tr().planning.compareAlternatives }}
-														</button>
-													}
-												</details>
-											}
 	</div>
 
-										<h4>{{ tr().planning.deltas }}</h4>
-										<ul>
-											@for (delta of decision.deltas; track $index) {
-												<li>
-													<strong>{{
-														formatIdentifier(delta.kind)
-													}}</strong>
-													@if (delta.fromDate || delta.date) {
-														· {{ delta.fromDate || delta.date }}
-													}
-													@if (delta.toDate) {
-														→ {{ delta.toDate }}
-													}
-													@if (delta.balanceId) {
-														· {{ delta.balanceId }}
-													}
-													@if (delta.remainingAfter !== undefined) {
-														· {{ delta.remainingBefore }} →
-														{{ delta.remainingAfter }}
-													}
-												</li>
-											}
-										</ul>
-										@if (traceState(); as state) {
-											<p class="trace-state-summary" role="status">
-												{{
-													traceMoment() === 'before'
-														? tr().planning.before
-														: tr().planning.after
-												}}: {{ state.placements.length }}
-												{{ tr().planning.placements }},
-												{{ state.earnedActivations.length }}
-												{{ tr().planning.activations }}
-												@for (balance of state.balances; track balance.id) {
-													<span class="trace-state-balance"
-														>{{ balance.id }}: {{ balance.remaining }}
-														{{ tr().planning.balanceRemaining }}
-														<small
-															>{{ tr().planning.details.available }}
-															{{ displayDate(balance.availableFrom) }}
-															·
-															{{ tr().planning.details.expires }}
-															{{
-																displayDate(balance.expiryDate)
-															}}</small
-														></span
-													>
-												}
-											</p>
-										}
-									}
-								} @else {
-									<p>{{ tr().planning.noDecisions }}</p>
-								}
-							</section>
-						}
-					</div>
-				} @else if (traceResolved()) {
-					<p role="status">{{ tr().planning.traceUnavailable }}</p>
-				}
-			</details>
-		}
-	</div>
-
-	@if (traceReplay()) {
-		<div class="replay-notice" role="status">
-			<span>{{ tr().planning.replayNotice }}</span>
-			<button type="button" class="quiet-button" (click)="showFinalPlan()">
-				{{ tr().planning.finalPlan }}
-			</button>
-		</div>
-	}
 	<p class="calendar-help">
 		<mat-icon aria-hidden="true">touch_app</mat-icon
 		>{{ declarationEntry() ? tr().bookedDays.help : tr().planning.calendarHelp }}
@@ -1037,7 +569,7 @@
 				<span class="legend-swatch today" aria-hidden="true"></span
 				>{{ tr().dayTypes.today }}
 			</li>
-			@if (planDetailsOpen() || traceReplay()) {
+			@if (planDetailsOpen()) {
 				<li>
 					<span class="legend-swatch current" aria-hidden="true"></span
 					>{{ tr().planning.currentPlacement }}
@@ -1049,62 +581,6 @@
 					>{{ tr().planning.explainedPeriod }}
 				</li>
 			}
-			@if (traceReplay() && counterfactual()) {
-				<li>
-					<span class="legend-symbol hypothetical-symbol" aria-hidden="true">~✓</span
-					>{{ tr().planning.eligible }}
-				</li>
-				<li>
-					<span class="legend-symbol hypothetical-symbol" aria-hidden="true">~×</span
-					>{{ tr().planning.ineligible }}
-				</li>
-			}
-			@if (traceReplay()) {
-				<li>
-					<span class="legend-symbol" aria-hidden="true">✓</span
-					>{{ traceStatusLabel('chosen') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">−</span
-					>{{ traceStatusLabel('evaluated-rejected') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">⌁</span
-					>{{ traceStatusLabel('pruned') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">?</span
-					>{{ traceStatusLabel('not-examined') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">×</span
-					>{{ traceStatusLabel('ineligible') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">+</span
-					>{{ traceChangeLabel('added') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">←</span
-					>{{ traceChangeLabel('moved-from') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">→</span
-					>{{ traceChangeLabel('moved-to') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">−</span
-					>{{ traceChangeLabel('removed') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">≈</span
-					>{{ traceChangeLabel('shared') }}
-				</li>
-				<li>
-					<span class="legend-symbol" aria-hidden="true">=</span
-					>{{ traceChangeLabel('unchanged') }}
-				</li>
-			}
 		</ul>
 	</div>
 
@@ -1129,7 +605,6 @@
 						[declarationPreview]="declarationPreview()"
 						[currentDate]="declarationEntry() ? null : currentPlacementDate()"
 						[explainedPeriod]="declarationEntry() ? undefined : explainedPeriod()"
-						[dateStatuses]="!declarationEntry() && traceReplay() ? dateStatuses() : {}"
 						(dateSelected)="!declarationEntry() && selectCalendarDate($event)"
 					></app-calendar-month>
 				</mat-card-content>
@@ -1144,22 +619,13 @@
 	let-beforeLabel="beforeLabel"
 	let-afterLabel="afterLabel"
 	let-audit="audit"
-	let-traceEffect="traceEffect"
 >
 	<section class="criteria-detail">
 		<h4>
-			{{
+			{{ tr().planning.details.criteria }}
-				traceEffect
-					? tr().planning.details.traceImpactTitle
-					: tr().planning.details.criteria
-			}}
 		</h4>
 		<p class="calculation-intro">
-			{{
+			{{ tr().planning.details.criteriaHelp }}
-				traceEffect
-					? tr().planning.details.traceImpactHelp
-					: tr().planning.details.criteriaHelp
-			}}
 		</p>
 		<table class="impact-table criteria-table">
 			<thead>
@@ -1178,7 +644,7 @@
 					@if (objective.numeric) {
 						<tr
 							[class.decisive-row]="
-								!traceEffect && objective.id === comparison.firstDecisiveObjective
+								objective.id === comparison.firstDecisiveObjective
 							"
 						>
 							<th scope="row">
@@ -1191,10 +657,7 @@
 										? tr().planning.details.higher
 										: tr().planning.details.lower
 								}}</small>
-								@if (
+								@if (objective.id === comparison.firstDecisiveObjective) {
-									!traceEffect &&
-									objective.id === comparison.firstDecisiveObjective
-								) {
 									<span class="decisive-label">{{
 										tr().planning.details.firstDifference
 									}}</span>
@@ -1218,10 +681,7 @@
 						@if (!objective.numeric) {
 							<li>
 								{{ objective.label }}
-								@if (
+								@if (objective.id === comparison.firstDecisiveObjective) {
-									!traceEffect &&
-									objective.id === comparison.firstDecisiveObjective
-								) {
 									<span class="decisive-label">{{
 										tr().planning.details.firstDifference
 									}}</span>
@@ -1347,11 +807,7 @@
 					{{ tr().planning.comparison.title }}
 				</h2>
 				<p id="comparison-intro">
-					{{
+					{{ tr().planning.explanation.moveHelp }}
-						traceReplay()
-							? tr().planning.explanation.traceHelp
-							: tr().planning.explanation.moveHelp
-					}}
 				</p>
 			</div>
 			<button
@@ -1376,11 +832,7 @@
 			} @else if (counterfactual(); as analysis) {
 				<div class="comparison-date-pair">
 					<div class="original-date">
-						<span>{{
+						<span>{{ tr().planning.explanation.plannedDate }}</span>
-							traceReplay()
-								? tr().planning.comparison.candidate
-								: tr().planning.explanation.plannedDate
-						}}</span>
 						<strong>{{ displayDate(analysis.placement.date) }}</strong>
 					</div>
 					<mat-icon aria-hidden="true">arrow_forward</mat-icon>
@@ -1469,7 +921,7 @@
 									}
 								</div>
 							</div>
-						} @else if (!traceReplay() && result.date === analysis.placement.date) {
+						} @else if (result.date === analysis.placement.date) {
 							<p class="comparison-empty">{{ tr().planning.explanation.sameDate }}</p>
 						} @else {
 							<div class="comparison-result-heading">
@@ -1488,20 +940,10 @@
 													{{ tr().planning.explanation.criterion }}
 												</th>
 												<th scope="col">
-													{{
+													{{ tr().planning.explanation.currentPlan }}
-														traceReplay()
-															? tr().planning.explanation
-																	.beforeDecision
-															: tr().planning.explanation.currentPlan
-													}}
 												</th>
 												<th scope="col">
-													{{
+													{{ tr().planning.explanation.alternative }}
-														traceReplay()
-															? tr().planning.explanation
-																	.withCandidate
-															: tr().planning.explanation.alternative
-													}}
 												</th>
 											</tr>
 										</thead>
@@ -1529,34 +971,14 @@
 						<details class="technical-details date-calculation-details">
 							<summary>{{ tr().planning.technicalDetails }}</summary>
 							<div class="calculation-content">
-								<p>
-									<strong>{{ tr().planning.historical }}:</strong>
-									{{
-										dateStatuses()[result.date]?.label ??
-											traceStatusLabel(
-												result.historicalStatus ?? 'not-examined'
-											)
-									}}
-								</p>
-								@if (dateStatuses()[result.date]?.reason; as historicalReason) {
-									<p>
-										<strong>{{ tr().planning.reason }}:</strong>
-										{{ historicalReason }}
-									</p>
-								}
 								@if (dateComparison(); as comparison) {
 									<ng-container
 										[ngTemplateOutlet]="calculationTable"
 										[ngTemplateOutletContext]="{
 											comparison,
-											beforeLabel: traceReplay()
+											beforeLabel: tr().planning.explanation.currentPlan,
-												? tr().planning.explanation.beforeDecision
+											afterLabel: tr().planning.explanation.alternative,
-												: tr().planning.explanation.currentPlan,
-											afterLabel: traceReplay()
-												? tr().planning.explanation.withCandidate
-												: tr().planning.explanation.alternative,
 											audit: result,
-											traceEffect: traceReplay(),
 										}"
 									/>
 								} @else {
@@ -1583,8 +1005,6 @@
 				{{
 					counterfactualError()
 						? tr().planning.retryCounterfactual
-						: traceReplay()
-							? tr().planning.comparison.backToTrace
 						: tr().planning.comparison.backToPlan
 				}}
 			</button>

src/app/components/calendar-year/calendar-year.scss

@@ -85,8 +85,7 @@ summary:focus-visible {
 }
 
 .results-header,
-.explanation-heading,
+.explanation-heading {
-.replay-notice {
 	display: flex;
 	flex-wrap: wrap;
 	align-items: center;
@@ -249,14 +248,12 @@ summary:focus-visible {
 }
 
 .placement-explanation,
-.outcome-explanation,
+.outcome-explanation {
-.trace-decisions {
 	display: grid;
 	gap: 1rem;
 	min-width: 0;
 }
-.placement-explanation,
+.placement-explanation {
-.trace-layout {
 	padding: 1.25rem;
 }
 .placement-explanation ul {
@@ -264,8 +261,7 @@ summary:focus-visible {
 	padding-inline-start: 1.25rem;
 }
 .break-story,
-.outcome-explanation,
+.outcome-explanation {
-.replay-notice {
 	padding: 1rem;
 	border-radius: var(--ui-radius-sm);
 	background: var(--ui-panel-bg);
@@ -339,17 +335,13 @@ summary:focus-visible {
 .compare-dates-button {
 	justify-self: start;
 }
-.placement-stepper,
+.placement-stepper {
-.trace-toolbar,
-.trace-decisions nav,
-.trace-phase-stepper {
 	display: flex;
 	flex-wrap: wrap;
 	align-items: center;
 	gap: 0.5rem;
 }
-.placement-stepper button,
+.placement-stepper button {
-.trace-phase-stepper button {
 	padding: 0.375rem;
 }
 output {
@@ -499,52 +491,6 @@ output {
 	box-shadow: none;
 }
 
-.trace-layout {
-	display: grid;
-	grid-template-columns: minmax(0, 0.35fr) minmax(0, 1fr);
-	gap: 1rem;
-}
-.trace-phases {
-	display: grid;
-	align-content: start;
-	gap: 0.5rem;
-	> button {
-		justify-content: space-between;
-		text-align: start;
-		overflow-wrap: anywhere;
-	}
-	.active {
-		border-inline-start: 4px solid var(--mat-sys-primary);
-	}
-	small {
-		color: var(--ui-text-secondary);
-		flex-shrink: 0;
-		white-space: nowrap;
-	}
-}
-.trace-phase-stepper {
-	justify-content: center;
-}
-.trace-decisions {
-	align-content: start;
-}
-.candidate-list {
-	display: grid;
-	gap: 0.5rem;
-	details {
-		padding: 0.5rem;
-		border: 1px solid var(--ui-border);
-		border-radius: var(--ui-radius-sm);
-		overflow-wrap: anywhere;
-	}
-}
-.trace-state-summary,
-.replay-notice {
-	padding: 0.75rem;
-	border: 1px solid var(--mat-sys-primary);
-	border-radius: var(--ui-radius-sm);
-}
-
 .loading-overlay {
 	position: absolute;
 	inset: 0;
@@ -576,18 +522,6 @@ output {
 	font-weight: 600;
 }
 
-@container calendar-year (max-width: 48rem) {
-	.trace-layout {
-		grid-template-columns: minmax(0, 1fr);
-	}
-	.trace-phases {
-		grid-template-columns: repeat(auto-fit, minmax(10rem, 1fr));
-	}
-	.trace-phase-stepper {
-		grid-column: 1 / -1;
-	}
-}
-
 @container calendar-year (max-width: 35rem) {
 	.plan-insights {
 		grid-template-columns: minmax(0, 1fr);
@@ -604,8 +538,7 @@ output {
 			font-size: 0.75rem;
 		}
 	}
-	.placement-explanation,
+	.placement-explanation {
-	.trace-layout {
 		padding: 0.875rem;
 	}
 	.placement-stepper {

src/app/components/calendar-year/calendar-year.ts

@@ -30,17 +30,12 @@ import {
 	MatDialogRef,
 	MatDialogTitle,
 } from '@angular/material/dialog';
-import {
+import { CalendarMonth, DeclarationPreview } from '../calendar-month/calendar-month';
-	CalendarMonth,
-	CalendarDayStatus,
-	DeclarationPreview,
-} from '../calendar-month/calendar-month';
 import { addPlanningDays } from '../../services/planning-date';
 import { isWorkingPlanningDate } from '../../services/declared-non-working-days';
 import {
 	CalendarService,
 	calendarProjectionHorizon,
-	DayType,
 	SelectedDates,
 	SelectableDayType,
 	VacDay,
@@ -50,10 +45,8 @@ import { UserInputService } from '../../services/user-input-service';
 import { CalendarSettingsService } from '../../services/calendar-settings-service';
 import { PlanningDurationService } from '../../services/planning-duration.service';
 import {
-	applyReplayDeltas,
 	CounterfactualAnalysis,
 	CounterfactualSelection,
-	LeavePlacement,
 	LeaveType,
 	DeclaredNonWorkingDay,
 	PlanExplanation,
@@ -64,15 +57,9 @@ import {
 	PlanningObjectiveVector,
 	PlanningOutcome,
 	PlanningReason,
-	PlanningTrace,
-	PlanningTraceCandidate,
-	PlanningTraceDecision,
-	PlanningTraceState,
 } from '../../services/leave-planner.service';
 
 type PlacementExplanation = PlanExplanation['placements'][number];
-type TraceMoment = 'before' | 'after';
-type TraceTransition = Readonly<{ before: PlanningTraceState; after: PlanningTraceState }>;
 
 @Component({
 	selector: 'app-calendar-year',
@@ -121,12 +108,8 @@ export class CalendarYear {
 	protected readonly planningOutcome = this.userInput.planningOutcomeSignal;
 	protected readonly planningExplanation = signal<PlanningExplanation | null>(null);
 	protected readonly explanationError = signal<PlanningReason | null>(null);
-	protected readonly planningTrace = this.userInput.planningTraceSignal;
-	protected readonly traceLoading = signal(false);
-	protected readonly traceResolved = this.userInput.traceResolvedSignal;
 	protected readonly selectedPlacementIndex = signal(0);
 	protected readonly planDetailsOpen = signal(false);
-	protected readonly traceOpen = signal(false);
 	private readonly planDetails = viewChild<ElementRef<HTMLDetailsElement>>('planDetails');
 	protected readonly counterfactual = signal<CounterfactualAnalysis | null>(null);
 	protected readonly selectedCounterfactualDate = signal<string | null>(null);
@@ -134,18 +117,7 @@ export class CalendarYear {
 	protected readonly counterfactualError = signal<string | null>(null);
 	protected readonly invalidComparisonDate = signal(false);
 	protected readonly comparisonDateInput = signal<Date | null>(null);
-	protected readonly tracePhaseIndex = signal(0);
-	protected readonly traceDecisionIndex = signal(0);
-	protected readonly traceCandidatePage = signal(0);
-	protected readonly traceMoment = signal<TraceMoment>('before');
-	protected readonly traceReplay = signal(false);
-	protected readonly selectedTraceDate = signal<string | null>(null);
 	protected readonly liveMessage = signal('');
-	private readonly historicalIneligibility = signal<ReadonlyMap<string, PlanningReason>>(
-		new Map(),
-	);
-	protected readonly historicalEligibilityLoading = signal(false);
-	protected readonly historicalEligibilityError = signal<string | null>(null);
 	protected readonly planningHorizon = signal<{ start: string; end: string } | null>(null);
 	protected readonly selectedDates = signal(new SelectedDates());
 	protected readonly declarationEntry = this.userInput.declarationEntrySignal;
@@ -179,21 +151,14 @@ export class CalendarYear {
 	protected readonly calendarDeclaredDays = computed<Readonly<Record<string, LeaveType>>>(() => {
 		const days = this.declarationEntry()
 			? this.userInput.declaredDaysSignal()
-			: (this.traceState()?.declaredDays ??
+			: (this.displayedPlan()?.declaredDays ?? this.resultDeclaredDays());
-				this.displayedPlan()?.declaredDays ??
-				this.resultDeclaredDays());
 		return Object.fromEntries(days.map(({ date, type }) => [date, type]));
 	});
 
 	private calculationVersion = 0;
 	private counterfactualVersion = 0;
-	private historicalEligibilityVersion = 0;
 	private activeCalculation: PlanningCalculationContext | null = null;
 	private runningCalculation: PlanningCalculationContext | null = null;
-	private readonly traceDecisionIndices = new WeakMap<
-		PlanningTrace,
-		ReadonlyMap<string, { decision: PlanningTraceDecision; ordinal: number }>
-	>();
 	private displayDateLocale = '';
 	private displayDateFormatter?: Intl.DateTimeFormat;
 
@@ -245,28 +210,6 @@ export class CalendarYear {
 		() => this.planExplanation()?.placements[this.selectedPlacementIndex()],
 	);
 
-	protected readonly selectedTracePhase = computed(
-		() => this.planningTrace()?.phases[this.tracePhaseIndex()],
-	);
-
-	protected readonly selectedTraceDecision = computed(
-		() => this.selectedTracePhase()?.decisions[this.traceDecisionIndex()],
-	);
-	protected readonly selectedTraceTransition = computed(() =>
-		this.traceReplay()
-			? this.replayTraceTransition(this.planningTrace(), this.selectedTraceDecision())
-			: undefined,
-	);
-
-	protected readonly visibleTraceCandidates = computed(() => {
-		const start = this.traceCandidatePage() * 50;
-		return this.selectedTraceDecision()?.candidates.slice(start, start + 50) ?? [];
-	});
-
-	protected readonly traceCandidatePages = computed(() =>
-		Math.max(1, Math.ceil((this.selectedTraceDecision()?.candidates.length ?? 0) / 50)),
-	);
-
 	protected readonly selectedCounterfactualResult = computed(() =>
 		this.counterfactual()?.results.find(
 			(result) => result.date === this.selectedCounterfactualDate(),
@@ -314,12 +257,9 @@ export class CalendarYear {
 		const analysis = this.counterfactual();
 		const comparison = this.selectedCounterfactualResult()?.comparison;
 		if (!analysis || !comparison) return undefined;
-		// Final-plan alternatives share a removed-day baseline. Compare their restored
+		// Compare restored alternatives against the displayed plan.
-		// plans; a trace candidate instead uses the exact state before its decision.
+		const before = analysis.results.find((result) => result.date === analysis.placement.date)
-		const before = this.traceReplay()
+			?.comparison?.after;
-			? comparison.before
-			: analysis.results.find((result) => result.date === analysis.placement.date)?.comparison
-					?.after;
 		return before
 			? {
 					before,
@@ -337,10 +277,6 @@ export class CalendarYear {
 		this.numericChanges(this.dateComparison()?.before, this.dateComparison()?.after),
 	);
 
-	protected readonly traceState = computed(() => {
-		return this.selectedTraceTransition()?.[this.traceMoment()];
-	});
-
 	protected readonly calendarSelectedDates = computed(() => {
 		if (this.declarationEntry()) {
 			const horizon = this.calendarHorizon();
@@ -352,176 +288,22 @@ export class CalendarYear {
 					})
 				: new SelectedDates();
 		}
-		const state = this.traceState();
+
-		return state
+		return this.selectedDates();
-			? this.calendarService.selectedDatesForPlan({
-					placements: [...state.placements],
-					declaredDays: state.declaredDays,
-					horizon: { ...state.horizon },
-				})
-			: this.selectedDates();
 	});
 
 	protected readonly currentPlacementDate = computed(() => {
-		if (this.traceReplay())
-			return (
-				this.selectedCounterfactualDate() ??
-				this.selectedTraceDate() ??
-				this.selectedTraceDecision()?.dates[0] ??
-				null
-			);
 		return this.planDetailsOpen() ? (this.selectedExplanation()?.placement.date ?? null) : null;
 	});
 
 	protected readonly explainedPeriod = computed(() =>
-		this.planDetailsOpen() && !this.traceReplay()
+		this.planDetailsOpen() ? this.selectedExplanation()?.timeOffPeriod : undefined,
-			? this.selectedExplanation()?.timeOffPeriod
-			: undefined,
 	);
 
-	protected readonly dateStatuses = computed<Readonly<Record<string, CalendarDayStatus>>>(() => {
-		const statuses: Record<string, CalendarDayStatus> = {};
-		const trace = this.planningTrace();
-		const closedDayDates = new Set<string>();
-		for (const selected of this.selectedDates().datesSelected) {
-			if (selected.type !== DayType.CLOSED_DAY || !selected.range.start) continue;
-			const day = selected.range.start;
-			closedDayDates.add(
-				`${String(day.getFullYear()).padStart(4, '0')}-${String(day.getMonth() + 1).padStart(2, '0')}-${String(day.getDate()).padStart(2, '0')}`,
-			);
-		}
-		if (this.traceReplay() && trace) {
-			const priority = new Map([
-				['ineligible', 0],
-				['not-examined', 1],
-				['pruned', 2],
-				['evaluated-rejected', 3],
-				['chosen', 4],
-			]);
-			for (
-				let timestamp = Date.parse(`${trace.initialState.horizon.start}T00:00:00Z`),
-					end = Date.parse(`${trace.initialState.horizon.end}T00:00:00Z`);
-				timestamp < end;
-				timestamp += 86_400_000
-			) {
-				const date = new Date(timestamp).toISOString().slice(0, 10);
-				statuses[date] = {
-					kind: 'not-examined',
-					label: this.traceStatusLabel('not-examined'),
-				};
-			}
-			for (const date of Object.keys(statuses)) {
-				const reason = this.nonWorkingDateReason(date, closedDayDates);
-				if (reason)
-					statuses[date] = {
-						kind: 'ineligible',
-						label: this.traceStatusLabel('ineligible'),
-						reason,
-					};
-			}
-			const explicitPriorities = new Map<string, number>();
-			for (const candidate of this.selectedTraceDecision()?.candidates ?? []) {
-				for (const date of candidate.dates ?? (candidate.date ? [candidate.date] : [])) {
-					const candidatePriority = priority.get(candidate.status)!;
-					if (candidatePriority > (explicitPriorities.get(date) ?? -1)) {
-						statuses[date] = {
-							kind: candidate.status,
-							label: this.traceStatusLabel(candidate.status),
-							reason: candidate.reason?.message,
-						};
-						explicitPriorities.set(date, candidatePriority);
-					}
-				}
-			}
-			for (const [date, reason] of this.historicalIneligibility()) {
-				if (statuses[date]?.kind !== 'not-examined') continue;
-				statuses[date] = {
-					kind: 'ineligible',
-					label: this.traceStatusLabel('ineligible'),
-					reason: this.reasonLabel(reason),
-				};
-			}
-			const decision = this.selectedTraceDecision();
-			if (decision) {
-				const changedDates = new Set<string>();
-				const setChange = (
-					date: string | undefined,
-					change: NonNullable<CalendarDayStatus['change']>,
-				) => {
-					if (!date) return;
-					changedDates.add(date);
-					statuses[date] = {
-						...(statuses[date] ?? {
-							kind: 'not-examined',
-							label: this.traceStatusLabel('not-examined'),
-						}),
-						change,
-						changeLabel: this.traceChangeLabel(change),
-					};
-				};
-				for (const delta of decision.branch?.deltas ?? decision.deltas) {
-					if (delta.kind === 'placement-added') setChange(delta.date, 'added');
-					else if (delta.kind === 'placement-removed') setChange(delta.date, 'removed');
-					else if (delta.kind === 'placement-moved') {
-						setChange(delta.fromDate, 'moved-from');
-						setChange(delta.toDate, 'moved-to');
-					} else if (delta.kind === 'placement-updated') setChange(delta.date, 'shared');
-				}
-				const transition = this.selectedTraceTransition();
-				for (const placement of [
-					...(transition?.before.placements ?? []),
-					...(transition?.after.placements ?? []),
-				]) {
-					if (!changedDates.has(placement.date)) setChange(placement.date, 'unchanged');
-				}
-			}
-			for (const result of this.counterfactual()?.results ?? []) {
-				const status = statuses[result.date];
-				const historicalStatus =
-					result.historicalStatus ??
-					(status && status.kind !== 'eligible' ? status.kind : 'not-examined');
-				statuses[result.date] = {
-					...status,
-					kind: historicalStatus,
-					label: this.traceStatusLabel(historicalStatus),
-					reason: result.historicalReason
-						? this.reasonLabel(result.historicalReason)
-						: status?.reason,
-					hypotheticalLabel:
-						result.status === 'eligible'
-							? this.tr().planning.eligible
-							: this.tr().planning.ineligible,
-					hypotheticalReason: result.reason?.message,
-				};
-			}
-			return statuses;
-		}
-		for (const result of this.counterfactual()?.results ?? []) {
-			const nonWorkingReason = this.nonWorkingDateReason(result.date, closedDayDates);
-			const historicalStatus =
-				result.historicalStatus ?? (nonWorkingReason ? 'ineligible' : 'not-examined');
-			statuses[result.date] = {
-				kind: historicalStatus,
-				label: this.traceStatusLabel(historicalStatus),
-				reason: result.historicalReason
-					? this.reasonLabel(result.historicalReason)
-					: historicalStatus === 'ineligible'
-						? nonWorkingReason
-						: undefined,
-				hypotheticalLabel:
-					result.status === 'eligible'
-						? this.tr().planning.eligible
-						: this.tr().planning.ineligible,
-				hypotheticalReason: result.reason?.message,
-			};
-		}
-		return statuses;
-	});
-
 	protected readonly months = computed(() => {
 		const horizon = this.calendarHorizon();
 		if (!horizon) return [];
-		const plan = this.traceState() ?? this.displayedPlan();
+		const plan = this.displayedPlan();
 		const projectionHorizon =
 			!this.declarationEntry() && plan
 				? (calendarProjectionHorizon(plan) ?? horizon)
@@ -555,7 +337,7 @@ export class CalendarYear {
 		effect(() => {
 			if (this.declarationEntry())
 				untracked(() => {
-					this.showFinalPlan();
+					this.clearCounterfactual();
 					this.liveMessage.set(this.tr().bookedDays.enter);
 				});
 		});
@@ -670,8 +452,6 @@ export class CalendarYear {
 		};
 		this.applyOutcome({ kind: 'PlanningIncomplete', completedStages: [], reasons: [reason] });
 		this.explanationError.set(reason);
-		this.traceLoading.set(false);
-		this.traceResolved.set(true);
 		this.loadingProgress.set(100);
 		this.isLoading.set(false);
 	}
@@ -683,20 +463,9 @@ export class CalendarYear {
 		this.planningOutcome.set(null);
 		this.planningExplanation.set(null);
 		this.explanationError.set(null);
-		this.planningTrace.set(null);
-		this.traceLoading.set(true);
-		this.traceResolved.set(false);
 		this.selectedPlacementIndex.set(0);
 		this.planDetailsOpen.set(false);
-		this.traceOpen.set(false);
 		this.clearCounterfactual();
-		this.tracePhaseIndex.set(0);
-		this.traceDecisionIndex.set(0);
-		this.traceCandidatePage.set(0);
-		this.traceMoment.set('before');
-		this.traceReplay.set(false);
-		this.clearHistoricalEligibility();
-		this.selectedTraceDate.set(null);
 		this.selectedDates.set(this.calendarService.getSelectedDatesForHorizon(horizon));
 		this.userInput.remainingVacationDaysSignal.set([]);
 	}
@@ -736,44 +505,6 @@ export class CalendarYear {
 				this.explanationError.set(reason);
 				this.liveMessage.set(`${this.tr().planning.explanationError} ${reason.message}`);
 			});
-		void calculation.trace
-			.then((trace) => {
-				if (calculation !== this.activeCalculation) return;
-				this.planningTrace.set(trace ?? null);
-				this.traceResolved.set(true);
-				this.liveMessage.set(
-					trace?.status === 'failed'
-						? this.tr().planning.traceUnavailable
-						: this.tr().planning.traceReady,
-				);
-			})
-			.catch((error: unknown) => {
-				if (calculation !== this.activeCalculation) return;
-				this.planningTrace.set({
-					status: 'failed',
-					initialState: {
-						calculationDate: calculation.snapshot.calculationDate,
-						horizon: calculation.snapshot.horizon,
-						...(calculation.snapshot.declaredDays
-							? { declaredDays: calculation.snapshot.declaredDays }
-							: {}),
-						balances: [],
-						placements: [],
-						earnedActivations: [],
-					},
-					phases: [],
-					completedStages: [],
-					error: {
-						code: 'trace-error',
-						message: error instanceof Error ? error.message : String(error),
-					},
-				});
-				this.traceResolved.set(true);
-				this.liveMessage.set(this.tr().planning.traceUnavailable);
-			})
-			.finally(() => {
-				if (calculation === this.activeCalculation) this.traceLoading.set(false);
-			});
 	}
 
 	private applyOutcome(outcome: PlanningOutcome): void {
@@ -833,7 +564,6 @@ export class CalendarYear {
 		if (!explanation?.placements.length) return;
 		const selected = Math.max(0, Math.min(index, explanation.placements.length - 1));
 		this.selectedPlacementIndex.set(selected);
-		this.traceReplay.set(false);
 		this.clearCounterfactual();
 		this.selectedCounterfactualDate.set(explanation.placements[selected].placement.date);
 		if (announce) this.liveMessage.set(this.placementAnnouncement());
@@ -863,19 +593,10 @@ export class CalendarYear {
 		if (open === this.planDetailsOpen()) return;
 		this.planDetailsOpen.set(open);
 		if (open) {
-			this.traceOpen.set(false);
 			this.selectPlacement(this.selectedPlacementIndex());
 		} else this.clearCounterfactual();
 	}
 
-	protected toggleTrace(event: Event): void {
-		const open = (event.currentTarget as HTMLDetailsElement).open;
-		if (open === this.traceOpen()) return;
-		this.traceOpen.set(open);
-		if (open) this.planDetailsOpen.set(false);
-		this.showFinalPlan();
-	}
-
 	protected stepPlacement(step: 'first' | 'previous' | 'next' | 'last'): void {
 		const last = (this.planExplanation()?.placements.length ?? 1) - 1;
 		const current = this.selectedPlacementIndex();
@@ -1064,7 +785,7 @@ export class CalendarYear {
 			return;
 		}
 		const declaredType = this.calendarDeclaredDays()[date];
-		if (declaredType && !this.traceReplay() && !this.counterfactual()) {
+		if (declaredType && !this.counterfactual()) {
 			this.liveMessage.set(
 				`${this.displayDate(date)}. ${this.tr().bookedDays.booked} (${this.translationService.getDayTypeLabel(declaredType)}). ${this.tr().bookedDays.fixed}`,
 			);
@@ -1074,212 +795,34 @@ export class CalendarYear {
 			this.invalidComparisonDate.set(false);
 			this.comparisonDateInput.set(new Date(`${date}T00:00:00`));
 		}
-		if (!this.traceReplay() && !this.counterfactual() && !this.counterfactualLoading()) {
+		if (!this.counterfactual() && !this.counterfactualLoading()) {
 			const index = this.planExplanation()?.placements.findIndex(
 				(explanation) => explanation.placement.date === date,
 			);
 			if (index !== undefined && index >= 0) {
 				this.planDetailsOpen.set(true);
-				this.traceOpen.set(false);
 				this.selectPlacement(index);
 				return;
 			}
 		}
-		if (this.traceReplay()) {
-			this.selectedTraceDate.set(date);
-			if (this.counterfactual()?.results.some((result) => result.date === date))
-				this.selectedCounterfactualDate.set(date);
-			this.liveMessage.set(this.dateStatusAnnouncement(date, this.dateStatuses()[date]));
-			return;
-		}
 		if (this.counterfactual()?.results.some((result) => result.date === date)) {
 			this.selectedCounterfactualDate.set(date);
-			this.liveMessage.set(this.dateStatusAnnouncement(date, this.dateStatuses()[date]));
+			this.liveMessage.set(this.dateStatusAnnouncement(date));
 		}
 	}
 
-	private dateStatusAnnouncement(date: string, status?: CalendarDayStatus): string {
+	private dateStatusAnnouncement(date: string): string {
+		const result = this.counterfactual()?.results.find((result) => result.date === date);
 		return [
 			date,
-			status?.label,
+			this.tr().planning.counterfactual,
-			status?.reason,
+			result ? this.tr().planning[result.status] : undefined,
-			status?.hypotheticalLabel
+			result?.reason ? this.reasonLabel(result.reason) : undefined,
-				? `${this.tr().planning.counterfactual}: ${status.hypotheticalLabel}`
-				: undefined,
-			status?.hypotheticalReason
-				? `${this.tr().planning.reason}: ${status.hypotheticalReason}`
-				: undefined,
-			status?.changeLabel,
 		]
 			.filter(Boolean)
 			.join('. ');
 	}
 
-	protected selectTracePhase(index: number): void {
-		const last = (this.planningTrace()?.phases.length ?? 1) - 1;
-		index = Math.max(0, Math.min(index, last));
-		this.tracePhaseIndex.set(index);
-		this.traceDecisionIndex.set(0);
-		this.traceCandidatePage.set(0);
-		this.traceMoment.set('before');
-		this.traceReplay.set(false);
-		this.clearHistoricalEligibility();
-		this.selectedTraceDate.set(null);
-		this.clearCounterfactual();
-		this.liveMessage.set(this.tracePhaseAnnouncement());
-	}
-
-	protected stepTracePhase(step: 'first' | 'previous' | 'next' | 'last'): void {
-		const last = (this.planningTrace()?.phases.length ?? 1) - 1;
-		const current = this.tracePhaseIndex();
-		const target =
-			step === 'first'
-				? 0
-				: step === 'last'
-					? last
-					: step === 'previous'
-						? current - 1
-						: current + 1;
-		if (target !== current) this.selectTracePhase(target);
-	}
-
-	protected selectTraceDecision(index: number): void {
-		const last = (this.selectedTracePhase()?.decisions.length ?? 1) - 1;
-		index = Math.max(0, Math.min(index, last));
-		this.traceDecisionIndex.set(index);
-		this.traceCandidatePage.set(0);
-		this.traceMoment.set('before');
-		this.traceReplay.set(true);
-		this.selectedTraceDate.set(this.selectedTraceDecision()?.dates[0] ?? null);
-		this.clearCounterfactual();
-		this.liveMessage.set(this.traceDecisionAnnouncement());
-		void this.loadHistoricalEligibility();
-	}
-
-	private selectedDecisionPlacement(decision: PlanningTraceDecision): LeavePlacement | undefined {
-		const placements = [
-			...decision.candidates.flatMap((candidate) =>
-				candidate.placement ? [candidate.placement] : [],
-			),
-			...(decision.branch?.deltas ?? decision.deltas).flatMap((delta) =>
-				delta.placement ? [delta.placement] : [],
-			),
-		];
-		const selectedDate = this.selectedTraceDate() ?? decision.dates[0];
-		return placements.find((placement) => placement.date === selectedDate) ?? placements[0];
-	}
-
-	private clearHistoricalEligibility(): void {
-		this.historicalEligibilityVersion++;
-		this.historicalIneligibility.set(new Map());
-		this.historicalEligibilityLoading.set(false);
-		this.historicalEligibilityError.set(null);
-	}
-
-	private async loadHistoricalEligibility(): Promise<void> {
-		const version = ++this.historicalEligibilityVersion;
-		this.historicalIneligibility.set(new Map());
-		this.historicalEligibilityLoading.set(false);
-		this.historicalEligibilityError.set(null);
-		const calculation = this.activeCalculation;
-		const decision = this.selectedTraceDecision();
-		const placement = decision && this.selectedDecisionPlacement(decision);
-		if (!this.traceReplay() || !calculation || !decision || !placement) return;
-		this.historicalEligibilityLoading.set(true);
-		this.liveMessage.set(this.tr().planning.historicalEligibilityLoading);
-		try {
-			const reasons = await calculation.historicalEligibility({
-				decisionId: decision.id,
-				placement,
-			});
-			if (
-				version !== this.historicalEligibilityVersion ||
-				calculation !== this.activeCalculation
-			)
-				return;
-			this.historicalIneligibility.set(
-				new Map(reasons.map(({ date, reason }) => [date, reason])),
-			);
-			this.liveMessage.set(this.tr().planning.historicalEligibilityReady);
-		} catch (error) {
-			if (version !== this.historicalEligibilityVersion) return;
-			this.historicalIneligibility.set(new Map());
-			const message = error instanceof Error ? error.message : String(error);
-			this.historicalEligibilityError.set(message);
-			this.liveMessage.set(`${this.tr().planning.historicalEligibilityError} ${message}`);
-		} finally {
-			if (version === this.historicalEligibilityVersion)
-				this.historicalEligibilityLoading.set(false);
-		}
-	}
-
-	protected retryHistoricalEligibility(): void {
-		void this.loadHistoricalEligibility();
-	}
-
-	protected stepTraceDecision(step: 'first' | 'previous' | 'next' | 'last'): void {
-		const last = (this.selectedTracePhase()?.decisions.length ?? 1) - 1;
-		const current = this.traceDecisionIndex();
-		const target =
-			step === 'first'
-				? 0
-				: step === 'last'
-					? last
-					: step === 'previous'
-						? current - 1
-						: current + 1;
-		if (target !== current) this.selectTraceDecision(target);
-	}
-
-	protected stepTraceCandidatePage(direction: -1 | 1): void {
-		const page = Math.max(
-			0,
-			Math.min(this.traceCandidatePage() + direction, this.traceCandidatePages() - 1),
-		);
-		if (page === this.traceCandidatePage()) return;
-		this.traceCandidatePage.set(page);
-		this.liveMessage.set(
-			`${this.tr().planning.page} ${this.traceCandidatePage() + 1} ${this.tr().planning.of} ${this.traceCandidatePages()}`,
-		);
-	}
-
-	protected showTraceMoment(moment: TraceMoment): void {
-		this.clearCounterfactual();
-		this.traceMoment.set(moment);
-		this.traceReplay.set(true);
-		this.liveMessage.set(`${this.tr().planning[moment]} ${this.traceDecisionAnnouncement()}`);
-		void this.loadHistoricalEligibility();
-	}
-
-	protected showFinalPlan(): void {
-		this.traceReplay.set(false);
-		this.clearHistoricalEligibility();
-		this.clearCounterfactual();
-		this.liveMessage.set(this.tr().planning.finalPlan);
-	}
-
-	protected analyzeTraceCandidate(candidate: PlanningTraceCandidate): void {
-		const decision = this.selectedTraceDecision();
-		if (!candidate.placement || !decision) return;
-		this.traceMoment.set('before');
-		this.traceReplay.set(true);
-		this.selectedTraceDate.set(candidate.placement.date);
-		void this.analyzeSelection(
-			{ decisionId: decision.id, placement: candidate.placement },
-			true,
-		);
-	}
-
-	private nonWorkingDateReason(
-		date: string,
-		closedDayDates: ReadonlySet<string>,
-	): string | undefined {
-		const day = new Date(`${date}T00:00:00`);
-		if (day.getDay() === 0 || day.getDay() === 6) return this.tr().dayTypes.weekend;
-		if (closedDayDates.has(date)) return this.tr().dayTypes.closedDay;
-		return undefined;
-	}
-
 	private counterfactualSelection: CounterfactualSelection | null = null;
 
 	private async analyzeSelection(
@@ -1295,12 +838,7 @@ export class CalendarYear {
 		this.counterfactualLoading.set(true);
 		this.invalidComparisonDate.set(false);
 		if (openDialog) this.openComparisonDialog();
-		const placement =
+		const placement = selection;
-			typeof selection === 'string'
-				? selection
-				: 'placement' in selection
-					? selection.placement
-					: selection;
 		this.liveMessage.set(
 			`${this.tr().planning.counterfactualLoading} ${typeof placement === 'string' ? this.displayDate(placement) : this.displayDate(placement.date)}`,
 		);
@@ -1312,9 +850,7 @@ export class CalendarYear {
 				this.counterfactual.set(result);
 				if (openDialog || this.comparisonDialog)
 					this.selectCalendarDate(
-						this.traceReplay()
+						this.nearbyComparisonDates()[0]?.date ?? result.placement.date,
-							? result.placement.date
-							: (this.nearbyComparisonDates()[0]?.date ?? result.placement.date),
 					);
 				this.liveMessage.set(this.tr().planning.counterfactualReady);
 			}
@@ -1362,113 +898,6 @@ export class CalendarYear {
 		this.comparisonDateInput.set(null);
 	}
 
-	private replayTraceTransition(
-		trace: PlanningTrace | null,
-		decision: PlanningTraceDecision | undefined,
-	): TraceTransition | undefined {
-		if (!trace || !decision) return undefined;
-		const state = {
-			balances: trace.initialState.balances.map((balance) => ({ ...balance })),
-			placements: new Map(
-				trace.initialState.placements.map((placement) => [
-					placement.date,
-					{ ...placement, ruleIds: [...placement.ruleIds] },
-				]),
-			),
-			earnedActivations: trace.initialState.earnedActivations.map((activation) => ({
-				...activation,
-				dates: [...activation.dates],
-			})),
-		};
-		const snapshot = (): PlanningTraceState => ({
-			calculationDate: trace.initialState.calculationDate,
-			horizon: { ...trace.initialState.horizon },
-			...(trace.initialState.declaredDays
-				? { declaredDays: trace.initialState.declaredDays }
-				: {}),
-			balances: state.balances.map((balance) => ({ ...balance })),
-			placements: [...state.placements.values()].map((placement) => ({
-				...placement,
-				ruleIds: [...placement.ruleIds],
-			})),
-			earnedActivations: state.earnedActivations.map((activation) => ({
-				...activation,
-				dates: [...activation.dates],
-			})),
-		});
-		if (decision.branch) {
-			const decisionIndex = this.getTraceDecisionIndex(trace);
-			const target = decisionIndex.get(decision.id);
-			if (!target) return undefined;
-			const branchAncestors: PlanningTraceDecision[] = [];
-			const visited = new Set([decision.id]);
-			let current = decision;
-			let committedParentOrdinal: number | undefined;
-			while (current.branch) {
-				branchAncestors.unshift(current);
-				const parentId = current.branch.parentDecisionId;
-				if (!parentId) break;
-				if (visited.has(parentId)) return undefined;
-				visited.add(parentId);
-				const parent = decisionIndex.get(parentId);
-				if (!parent) return undefined;
-				if (!parent.decision.branch) {
-					committedParentOrdinal = parent.ordinal;
-					break;
-				}
-				current = parent.decision;
-			}
-			const branchRoot = branchAncestors[0];
-			const branchRootIndex = branchRoot && decisionIndex.get(branchRoot.id)?.ordinal;
-			if (branchRootIndex === undefined || target.ordinal < branchRootIndex) return undefined;
-			const replayThrough = committedParentOrdinal ?? branchRootIndex - 1;
-			if (replayThrough >= branchRootIndex) return undefined;
-			let ordinal = 0;
-			for (const phase of trace.phases) {
-				for (const prior of phase.decisions) {
-					if (ordinal++ > replayThrough) break;
-					applyReplayDeltas(state, prior.deltas);
-				}
-				if (ordinal > replayThrough) break;
-			}
-			for (const ancestor of branchAncestors.slice(0, -1))
-				applyReplayDeltas(state, ancestor.branch!.deltas);
-			const before = snapshot();
-			applyReplayDeltas(state, decision.branch.deltas);
-			return { before, after: snapshot() };
-		}
-		for (const phase of trace.phases) {
-			for (const prior of phase.decisions) {
-				if (prior.id === decision.id) {
-					const before = snapshot();
-					applyReplayDeltas(state, prior.deltas);
-					return { before, after: snapshot() };
-				}
-				applyReplayDeltas(state, prior.deltas);
-			}
-		}
-		return undefined;
-	}
-
-	private getTraceDecisionIndex(
-		trace: PlanningTrace,
-	): ReadonlyMap<string, { decision: PlanningTraceDecision; ordinal: number }> {
-		let index = this.traceDecisionIndices.get(trace);
-		if (!index) {
-			const decisions = new Map<
-				string,
-				{ decision: PlanningTraceDecision; ordinal: number }
-			>();
-			let ordinal = 0;
-			for (const phase of trace.phases)
-				for (const decision of phase.decisions)
-					decisions.set(decision.id, { decision, ordinal: ordinal++ });
-			index = decisions;
-			this.traceDecisionIndices.set(trace, index);
-		}
-		return index;
-	}
-
 	protected placementAnnouncement(): string {
 		const selected = this.selectedExplanation();
 		const count = this.planExplanation()?.placements.length ?? 0;
@@ -1480,18 +909,6 @@ export class CalendarYear {
 		return explanation.contributions.some((contribution) => contribution.kind === 'at-risk');
 	}
 
-	protected tracePhaseAnnouncement(): string {
-		const phases = this.planningTrace()?.phases ?? [];
-		const phase = phases[this.tracePhaseIndex()];
-		return `${this.tr().planning.phases} ${this.tracePhaseIndex() + 1} ${this.tr().planning.of} ${phases.length}${phase ? `: ${this.phaseLabel(phase.name)}` : ''}`;
-	}
-
-	protected traceDecisionAnnouncement(): string {
-		const decisions = this.selectedTracePhase()?.decisions ?? [];
-		const decision = decisions[this.traceDecisionIndex()];
-		return `${this.tr().planning.decision} ${this.traceDecisionIndex() + 1} ${this.tr().planning.of} ${decisions.length}${decision?.dates.length ? `: ${decision.dates.join(', ')}` : ''}`;
-	}
-
 	protected hasPlannerError(): boolean {
 		const outcome = this.planningOutcome();
 		return (
@@ -1627,22 +1044,10 @@ export class CalendarYear {
 		return value instanceof Date ? value.toISOString().slice(0, 10) : value.slice(0, 10);
 	}
 
-	protected traceStatusLabel(status: PlanningTraceCandidate['status']): string {
-		return this.tr().planning.traceStatuses[status];
-	}
-
 	protected reasonLabel(reason: PlanningReason): string {
 		return this.tr().planning.explanation.unavailable[reason.code] ?? reason.message;
 	}
 
-	protected tracePhaseStatusLabel(status: 'completed' | 'interrupted' | 'not-run'): string {
-		return this.tr().planning.tracePhaseStatuses[status];
-	}
-
-	protected traceChangeLabel(change: NonNullable<CalendarDayStatus['change']>): string {
-		return this.tr().planning.traceChanges[change];
-	}
-
 	protected formatIdentifier(value: string): string {
 		return value.replaceAll('-', ' ').replaceAll(':', ': ');
 	}

src/app/components/user-input/user-input.html

@@ -173,113 +173,7 @@
 								@if (day.suggestion) {
 									<p>{{ day.suggestion }}</p>
 								}
-								<details
-									name="remaining-balances"
-									[open]="historyBalanceId() === day.id"
-									(toggle)="toggleRemainingHistory(day.id, $event)"
-								>
-									<summary
-										[attr.aria-label]="
-											tr().userInput.remainingWhy +
-											' : ' +
-											day.title +
-											'. ' +
-											day.validity
-										"
-									>
-										{{ tr().userInput.remainingWhy }}
-									</summary>
 								<p>{{ day.horizon }}</p>
-									@if (historyBalanceId() === day.id) {
-										@if (!traceResolved()) {
-											<p role="status">{{ tr().loading }}</p>
-										} @else {
-											@if (!trace() || trace()?.status === 'failed') {
-												<p>{{ tr().planning.traceUnavailable }}</p>
-											}
-											@if (remainingHistory().length) {
-												<p>{{ tr().userInput.remainingHistoryHelp }}</p>
-												<ol
-													class="remaining-history"
-													[attr.start]="historyPage() * 20 + 1"
-												>
-													@for (
-														attempt of visibleHistory();
-														track $index
-													) {
-														<li>
-															<strong>{{ attempt.date }}</strong> ·
-															{{ attempt.status }}
-															@if (attempt.phase) {
-																<p>{{ attempt.phase }}</p>
-															}
-															@if (attempt.reason) {
-																<p>{{ attempt.reason }}</p>
-															}
-															@for (
-																criterion of attempt.criteria;
-																track $index
-															) {
-																<p
-																	[class.decisive]="
-																		criterion.decisive
-																	"
-																>
-																	@if (criterion.decisive) {
-																		{{
-																			tr().planning.details
-																				.firstDifference
-																		}}
-																		:
-																	}
-																	{{ criterion.text }}
-																</p>
-															}
-														</li>
-													}
-												</ol>
-												@if (historyPageCount() > 1) {
-													<nav
-														class="history-pagination"
-														[attr.aria-label]="tr().planning.candidates"
-													>
-														<button
-															mat-button
-															type="button"
-															[disabled]="historyPage() === 0"
-															(click)="
-																historyPage.set(historyPage() - 1)
-															"
-														>
-															{{ tr().planning.previousCandidates }}
-														</button>
-														<span
-															>{{ tr().planning.page }}
-															{{ historyPage() + 1 }}
-															{{ tr().planning.of }}
-															{{ historyPageCount() }}</span
-														>
-														<button
-															mat-button
-															type="button"
-															[disabled]="
-																historyPage() + 1 >=
-																historyPageCount()
-															"
-															(click)="
-																historyPage.set(historyPage() + 1)
-															"
-														>
-															{{ tr().planning.nextCandidates }}
-														</button>
-													</nav>
-												}
-											} @else if (trace() && trace()?.status !== 'failed') {
-												<p>{{ tr().userInput.remainingNoEvaluations }}</p>
-											}
-										}
-									}
-								</details>
 							</li>
 						}
 					</ul>

src/app/components/user-input/user-input.scss

@@ -239,33 +239,13 @@ form {
 	}
 }
 
-.remaining-balances,
+.remaining-balances {
-.remaining-history {
 	display: grid;
 	gap: 1rem;
 	margin: 0.5rem 0;
 	padding-inline-start: 1.25rem;
 }
 
-.remaining-day-detail summary {
-	min-height: 2.75rem;
-	align-content: center;
-	cursor: pointer;
-	text-decoration: underline;
-	text-underline-offset: 0.25em;
-}
-
-.decisive {
-	font-weight: 700;
-}
-
-.history-pagination {
-	display: flex;
-	flex-wrap: wrap;
-	align-items: center;
-	gap: 0.5rem;
-}
-
 :host {
 	display: block;
 	container: user-input / inline-size;

src/app/components/user-input/user-input.spec.ts

@@ -98,11 +98,9 @@ describe('UserInput', () => {
 		} finally {
 			vi.stubGlobal('window', browserWindow);
 		}
-		const [outcome, trace] = await Promise.all([calculation.outcome, calculation.trace]);
+		const outcome = await calculation.outcome;
 		userInputService.planningSnapshotSignal.set(calculation.snapshot);
 		userInputService.planningOutcomeSignal.set(outcome);
-		userInputService.planningTraceSignal.set(trace ?? null);
-		userInputService.traceResolvedSignal.set(true);
 		fixture.detectChanges();
 	}
 
@@ -134,7 +132,7 @@ describe('UserInput', () => {
 		expect(card.textContent).toBe(explanation);
 	});
 
-	it('shows genuine recorded attempts on demand for usable leave kept for later', async () => {
+	it('explains usable leave kept for later and incomplete balances without attempt controls', async () => {
 		TestBed.inject(TranslationService).setLanguage('fr');
 		await calculate({
 			horizon: { start: '2024-06-04', end: '2024-06-13' },
@@ -158,17 +156,9 @@ describe('UserInput', () => {
 		expect(card.textContent).not.toContain('Disponible seulement');
 		expect(root.querySelector('.remaining-history')).toBeNull();
 		const outcome = JSON.stringify(userInputService.planningOutcomeSignal());
-		const trace = JSON.stringify(userInputService.planningTraceSignal());
+		expect(card.querySelector('details')).toBeNull();
-		const details = root.querySelector<HTMLDetailsElement>('.remaining-day-detail details')!;
+		expect(card.textContent).not.toContain('trace');
-		details.open = true;
-		details.dispatchEvent(new Event('toggle'));
-		fixture.detectChanges();
-		expect(root.querySelectorAll('.remaining-history > li').length).toBeGreaterThan(0);
-		expect(details.textContent).toContain('Ces dates ont réellement été examinées');
-		expect(details.textContent).toContain(presets[3].name);
-		expect(details.textContent).toContain('Évalué et rejeté');
 		expect(JSON.stringify(userInputService.planningOutcomeSignal())).toBe(outcome);
-		expect(JSON.stringify(userInputService.planningTraceSignal())).toBe(trace);
 
 		const plan = userInputService.displayedPlanSignal()!;
 		userInputService.planningOutcomeSignal.set({
@@ -177,17 +167,11 @@ describe('UserInput', () => {
 			completedStages: [],
 			reasons: [{ code: 'user-cancelled', message: 'Cancelled' }],
 		});
-		userInputService.planningTraceSignal.set(null);
 		fixture.detectChanges();
 		expect(card.textContent).toContain('Sa non-utilisation n’est pas une décision définitive');
 		expect(card.textContent).not.toContain('Conservé pour plus tard');
 		expect(root.querySelector('.remaining-history')).toBeNull();
-		details.open = true;
+		expect(card.querySelector('details')).toBeNull();
-		details.dispatchEvent(new Event('toggle'));
-		fixture.detectChanges();
-		expect(details.textContent).toContain(
-			TestBed.inject(TranslationService).tr().planning.traceUnavailable,
-		);
 	});
 
 	it('describes Calculate with an indicative range that follows unsubmitted edits', () => {

src/app/components/user-input/user-input.ts

@@ -1,11 +1,4 @@
-import {
+import { Component, computed, effect, inject, ChangeDetectionStrategy } from '@angular/core';
-	Component,
-	computed,
-	effect,
-	inject,
-	signal,
-	ChangeDetectionStrategy,
-} from '@angular/core';
 import { MatInputModule } from '@angular/material/input';
 import { MatFormFieldModule } from '@angular/material/form-field';
 import { MatDatepickerModule } from '@angular/material/datepicker';
@@ -78,10 +71,6 @@ export class UserInput {
 		return this.translationService.tr;
 	}
 
-	protected readonly trace = this.userInputService.planningTraceSignal;
-	protected readonly traceResolved = this.userInputService.traceResolvedSignal;
-	protected readonly historyBalanceId = signal<string | null>(null);
-	protected readonly historyPage = signal(0);
 	protected readonly remainingDays = computed(() =>
 		(this.userInputService.displayedPlanSignal()?.remainingBalances ?? []).reduce(
 			(total, balance) => total + balance.quantity,
@@ -145,57 +134,8 @@ export class UserInput {
 		});
 	});
 
-	protected readonly remainingHistory = computed(() => {
-		const id = this.historyBalanceId();
-		if (!id) return [];
-		return (
-			this.trace()?.phases.flatMap((phase) =>
-				phase.decisions.flatMap((decision) =>
-					decision.candidates
-						.filter((candidate) => candidate.placement?.balanceId === id)
-						.map((candidate) => ({ candidate, phase: phase.name })),
-				),
-			) ?? []
-		);
-	});
-	protected readonly historyPageCount = computed(() =>
-		Math.ceil(this.remainingHistory().length / 20),
-	);
-	protected readonly visibleHistory = computed(() =>
-		this.remainingHistory()
-			.slice(this.historyPage() * 20, (this.historyPage() + 1) * 20)
-			.map(({ candidate, phase }) => ({
-				date: (candidate.dates ?? (candidate.date ? [candidate.date] : []))
-					.map((date) => this.translationService.formatPlanningDate(date))
-					.join(', '),
-				phase: this.tr().planning.explanation.stages[phase] ?? this.criterionLabel(phase),
-				status: this.tr().planning.traceStatuses[candidate.status],
-				reason: candidate.reason
-					? (this.tr().userInput.remainingCandidateReasons[candidate.reason.code] ??
-						this.tr().planning.explanation.unavailable[candidate.reason.code] ??
-						this.tr().userInput.remainingCandidateReasons['unknown'])
-					: '',
-				criteria: (candidate.technicalComparison ?? []).flatMap((value) => {
-					const label = this.criterionLabel(value.name);
-					return label
-						? [
-								{
-									text: `${label} : ${value.before} → ${value.after}`,
-									decisive: value.name === candidate.firstDecisiveComparator,
-								},
-							]
-						: [];
-				}),
-			})),
-	);
-
 	constructor() {
 		effect(() => this.dateAdapter.setLocale(this.translationService.locale()));
-		effect(() => {
-			this.userInputService.planningOutcomeSignal();
-			this.historyBalanceId.set(null);
-			this.historyPage.set(0);
-		});
 	}
 
 	protected setPlanningDate(field: 'start' | 'lastPlanningDate', value: Date | null): void {
@@ -213,29 +153,6 @@ export class UserInput {
 		);
 	}
 
-	private criterionLabel(name: string): string | undefined {
-		const id = name.replace(/^protected:/, '');
-		if (id.startsWith('optimization:')) return this.ruleName(id.slice('optimization:'.length));
-		const key =
-			id === 'obligations'
-				? 'obligation-validity'
-				: id.startsWith('preference:')
-					? 'preference'
-					: id;
-		return this.tr().planning.explanation.objectives[key]?.label.replace(
-			'{rule}',
-			this.ruleName(id.slice('preference:'.length)),
-		);
-	}
-
-	protected toggleRemainingHistory(id: string, event: Event): void {
-		const open = (event.currentTarget as HTMLDetailsElement).open;
-		if (open && id !== this.historyBalanceId()) {
-			this.historyPage.set(0);
-			this.historyBalanceId.set(id);
-		} else if (!open && id === this.historyBalanceId()) this.historyBalanceId.set(null);
-	}
-
 	protected hasRemainingDays = computed(() => this.remainingDays() > 0);
 
 	protected get daysOff() {

src/app/services/calendar-objectives.worker.spec.ts

@@ -13,6 +13,8 @@ describe('calendar objectives in the real worker', () => {
 	let directory: string;
 	let bundle: string;
 	const threads = new Set<NodeWorker>();
+	const messages: string[] = [];
+	let stopped = 0;
 
 	beforeAll(async () => {
 		directory = mkdtempSync(join(tmpdir(), 'vac-calendar-worker-'));
@@ -30,6 +32,8 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 	});
 
 	beforeEach(() => {
+		messages.length = 0;
+		stopped = 0;
 		vi.setSystemTime(new Date('2024-04-01T12:00:00Z'));
 		class BrowserWorker {
 			onmessage: ((event: MessageEvent) => void) | null = null;
@@ -37,13 +41,17 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 			private readonly thread = new NodeWorker(bundle);
 			constructor() {
 				threads.add(this.thread);
-				this.thread.on('message', (data) => this.onmessage?.({ data } as MessageEvent));
+				this.thread.on('message', (data) => {
+					messages.push(data.type);
+					this.onmessage?.({ data } as MessageEvent);
+				});
 				this.thread.on('error', () => this.onerror?.());
 			}
 			postMessage(message: unknown) {
 				this.thread.postMessage(message);
 			}
 			terminate() {
+				stopped++;
 				void this.thread.terminate();
 			}
 		}
@@ -109,14 +117,19 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 			if (explanation?.kind !== 'PlanExplanation')
 				throw new Error('Expected a worker explanation');
 			expect(explanation.placements[0].firstDecisiveObjective).toBe(first);
-			expect((await calculation.trace)?.phases.map((phase) => phase.name)).toEqual([
+			await calculation.timings;
-				'validation',
+			expect(new Set(messages)).toEqual(
-				'obligations',
+				new Set([
-				first,
+					'heartbeat',
-				`optimization:${rules[1].id}`,
+					'progress',
-				'expiry',
+					'checkpoint',
-				'dates',
+					'result',
-			]);
+					'explanation',
+					'artifacts',
+				]),
+			);
+			expect(messages.indexOf('result')).toBeLessThan(messages.indexOf('explanation'));
+			expect(stopped).toBe(1);
 			const comparison = await calculation.analyzeCounterfactual(plan.placements[0]);
 			if (comparison.kind !== 'Counterfactual')
 				throw new Error('Expected a worker comparison');
@@ -169,29 +182,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 				name: 'Captured supporting economy',
 				configuration: OPTIMIZATION_PRESETS.supportingPlacements,
 			});
-			const trace = await calculation.trace;
-			expect(trace?.phases.map(({ name }) => name)).toEqual([
-				'validation',
-				'obligations',
-				`optimization:${rules[0].id}`,
-				`optimization:${rules[1].id}`,
-				'expiry',
-				'dates',
-			]);
-			const candidates = trace?.phases.flatMap(({ decisions }) =>
-				decisions.flatMap(({ candidates }) => candidates),
-			);
-			expect(candidates).toContainEqual(
-				expect.objectContaining({
-					status: economyFirst ? 'evaluated-rejected' : 'chosen',
-					dates: ['2026-11-12', '2026-11-13'],
-					comparison: expect.objectContaining({
-						firstDecisiveObjective: economyFirst
-							? 'optimization:economy'
-							: 'optimization:holiday',
-					}),
-				}),
-			);
 			const explanation = await calculation.explanation;
 			if (explanation?.kind !== 'PlanExplanation') throw new Error('Expected an explanation');
 			if (economyFirst) {

src/app/services/calendar-service.ts

@@ -11,7 +11,7 @@ import {
 	LeaveType,
 	PlanOutcome,
 	PlanningReason,
-	PlanningTraceState,
+	PlanningStateSnapshot,
 	RemainingClassification,
 } from './leave-planner.service';
 import { addPlanningDays, addPlanningYears, planningDateInParis } from './planning-date';
@@ -19,8 +19,8 @@ import { addPlanningDays, addPlanningYears, planningDateInParis } from './planni
 dayjs.extend(weekOfYear);
 dayjs.extend(isoWeek);
 
-type CalendarPlan = Pick<PlanningTraceState, 'placements' | 'declaredDays'> & {
+type CalendarPlan = Pick<PlanningStateSnapshot, 'placements' | 'declaredDays'> & {
-	horizon?: PlanningTraceState['horizon'];
+	horizon?: PlanningStateSnapshot['horizon'];
 	timeOffPeriods?: PlanOutcome['timeOffPeriods'];
 };
 

src/app/services/leave-planner-calendar-objectives.spec.ts

@@ -417,7 +417,7 @@ describe('composed calendar objectives', () => {
 		expect(ordinary.metrics.holidayWeekValue).toBe(0);
 	});
 
-	it('uses the same first calendar objective in the plan explanation, trace and date comparison', () => {
+	it('uses the same first calendar objective in the explanation and date comparison', () => {
 		for (const rules of [
 			[holiday, gain],
 			[gain, holiday],
@@ -439,15 +439,6 @@ describe('composed calendar objectives', () => {
 				'balance-expiry',
 				'placement-date',
 			]);
-			const comparisons = artifacts.trace?.phases
-				.flatMap((phase) => phase.decisions)
-				.flatMap((decision) => decision.candidates)
-				.filter((candidate) => candidate.status === 'chosen' && candidate.comparison);
-			expect(
-				comparisons?.some(
-					(candidate) => candidate.comparison?.firstDecisiveObjective === first,
-				),
-			).toBe(true);
 			const placement = rules[0].id === 'holiday' ? plan.placements[1] : plan.placements[0];
 			const alternative = rules[0].id === 'holiday' ? '2024-04-30' : '2024-05-02';
 			const comparison = analyzeCounterfactualInternal(
@@ -455,11 +446,16 @@ describe('composed calendar objectives', () => {
 				plan,
 				placement,
 				artifacts.finalState,
-				{ removeDate: placement.date, compareOriginalState: true },
 			);
+			const original = comparison.results.find((result) => result.date === placement.date)
+				?.comparison?.after;
+			const alternativeVector = comparison.results.find(
+				(result) => result.date === alternative,
+			)?.comparison?.after;
 			expect(
-				comparison.results.find((result) => result.date === alternative)?.comparison
+				alternativeVector?.objectives.find(
-					?.firstDecisiveObjective,
+					(objective, index) => objective.value !== original?.objectives[index].value,
+				)?.id,
 			).toBe(first);
 		}
 	});

src/app/services/leave-planner-cancellation.spec.ts

@@ -1,10 +1,6 @@
 import { createOptimizationPresetRules } from './rule-service';
 import { vi } from 'vitest';
-import {
+import { createPlanningCalculation, type PlanningIncompleteOutcome } from './leave-planner.service';
-	createPlanningCalculation,
-	type PlanningIncompleteOutcome,
-	type PlanningTraceUpdate,
-} from './leave-planner.service';
 
 const request = {
 	horizon: { start: '2024-01-01', end: '2025-01-01' },
@@ -46,7 +42,6 @@ describe('user cancellation', () => {
 			kind: 'PlanningIncomplete',
 			reasons: [{ code: 'user-cancelled' }],
 		});
-		expect((await calculation.trace)?.status).toBe('incomplete');
 	});
 
 	it('retains the same declared-only periods and metrics in a cancelled valid plan', async () => {
@@ -96,7 +91,6 @@ describe('user cancellation', () => {
 			placements: [],
 			incomplete: { reason: { code: 'user-cancelled' } },
 		});
-		expect(artifacts.trace?.status).toBe('incomplete');
 		expect(artifacts.finalState?.declaredDays).toEqual(submitted.declaredDays);
 	});
 
@@ -193,17 +187,15 @@ describe('user cancellation', () => {
 			kind: 'IncompleteExplanation',
 			reason: { code: 'stale-calculation' },
 		});
-		expect((await replaced.trace)?.error).toMatchObject({ code: 'stale-calculation' });
 		expect(await current.outcome).toMatchObject({ kind: 'Plan' });
-		await current.trace;
 	});
 
-	it('retains a plan at least as good as every valid candidate actually evaluated before cancellation', async () => {
+	it('retains a plan at least as good as every valid checkpoint before cancellation', async () => {
 		const core = await import('./leave-planner.core');
 		let cancelled = false;
 		let artifacts: import('./leave-planner.core').PlanningArtifacts = {};
-		const outcome = await core.calculatePlanningAsyncInternal(
+		const checkpoints: (readonly import('./leave-planner.core').PlanningObjective[])[] = [];
-			{
+		const submitted = {
 			horizon: request.horizon,
 			balances: [{ id: 'cp', type: 'cp', quantity: 2, expiryDate: '2024-12-31' }],
 			rules: [
@@ -224,8 +216,18 @@ describe('user cancellation', () => {
 			progress: (stage: string) => {
 				if (stage === 'optimization:default-longest-work-sequence') cancelled = true;
 			},
+		};
+		const outcome = await core.calculatePlanningAsyncInternal(
+			submitted,
+			(plan, state) => {
+				if (!state) return;
+				const explained = core.explainIncompleteCheckpoint(submitted, plan, state, {
+					code: 'user-cancelled',
+					message: 'Cancelled',
+				}).explanation;
+				if (explained?.kind === 'PlanExplanation' && explained.placements.length)
+					checkpoints.push(explained.placements[0].objectiveVector.objectives);
 			},
-			undefined,
 			(value) => (artifacts = value),
 			undefined,
 			undefined,
@@ -235,36 +237,25 @@ describe('user cancellation', () => {
 			kind: 'PlanningIncomplete',
 			reasons: [{ code: 'user-cancelled' }],
 		});
-		if (artifacts.explanation?.kind !== 'PlanExplanation' || !artifacts.trace)
+		if (artifacts.explanation?.kind !== 'PlanExplanation')
-			throw new Error('Expected a retained plan explanation and its original trace.');
+			throw new Error('Expected a retained plan explanation.');
 		const retained = artifacts.explanation.placements[0].objectiveVector.objectives;
-		const evaluated = artifacts.trace.phases.flatMap((phase) =>
+		expect(checkpoints.length).toBeGreaterThan(0);
-			phase.decisions.flatMap((decision) =>
+		for (const candidate of checkpoints) {
-				decision.candidates.flatMap((candidate) =>
-					candidate.comparison?.after.objectives[0].value === 0
-						? [candidate.comparison.after.objectives]
-						: [],
-				),
-			),
-		);
-		expect(evaluated.length).toBeGreaterThan(0);
-		for (const candidate of evaluated) {
 			expect(candidate.map(({ id }) => id)).toEqual(retained.map(({ id }) => id));
-			const firstDifference = retained.findIndex(
+			const first = retained.findIndex(
 				(objective, index) => objective.value !== candidate[index].value,
 			);
-			if (firstDifference < 0) continue;
+			if (first < 0) continue;
-			const chosen = retained[firstDifference];
-			const alternative = candidate[firstDifference];
 			expect(
-				chosen.direction === 'minimize'
+				retained[first].direction === 'minimize'
-					? chosen.value < alternative.value
+					? retained[first].value < candidate[first].value
-					: chosen.value > alternative.value,
+					: retained[first].value > candidate[first].value,
 			).toBe(true);
 		}
 	});
 
-	it('requests interruption before a valid plan without terminating trace delivery', async () => {
+	it('requests interruption before a valid plan and terminates after required delivery', async () => {
 		const calculation = createPlanningCalculation(request);
 		calculation.cancel();
 		calculation.cancel();
@@ -285,13 +276,11 @@ describe('user cancellation', () => {
 		expect(await calculation.outcome).toEqual({ ...cancelled, calculationDate: '2024-01-01' });
 		expect(currentWorker().terminate).not.toHaveBeenCalled();
 		currentWorker().emit({ type: 'artifacts', artifacts: {} });
-		await calculation.trace;
 		expect(currentWorker().terminate).toHaveBeenCalledOnce();
 	});
 
-	it('drains records queued before and after cancellation while keeping the partial plan on artifact error', async () => {
+	it('keeps a cancelled partial plan after explanation delivery fails', async () => {
 		const core = await import('./leave-planner.core');
-		const updates: PlanningTraceUpdate[] = [];
 		let interrupted = false;
 		let artifacts: import('./leave-planner.core').PlanningArtifacts = {};
 		const submitted = {
@@ -302,8 +291,6 @@ describe('user cancellation', () => {
 		const cancelled = await core.calculatePlanningAsyncInternal(
 			{
 				...submitted,
-				traceProgress: (_: number, update: PlanningTraceUpdate) =>
-					updates.push(structuredClone(update)),
 				progress: (stage: string) => {
 					if (stage === 'optimization:default-non-working-day-gain') interrupted = true;
 				},
@@ -314,20 +301,9 @@ describe('user cancellation', () => {
 			undefined,
 			() => interrupted,
 		);
-		if (cancelled.kind !== 'PlanningIncomplete' || !cancelled.incumbent || !artifacts.trace)
+		if (cancelled.kind !== 'PlanningIncomplete' || !cancelled.incumbent)
-			throw new Error('Expected a cancelled fixture with a valid plan and original trace.');
+			throw new Error('Expected a cancelled fixture with a valid plan.');
 		const calculation = createPlanningCalculation(submitted);
-		const operations = updates.flatMap(({ operations }) => operations);
-		const split = Math.floor(operations.length / 2);
-		currentWorker().emit({
-			type: 'trace-update',
-			totalMs: 0,
-			acknowledge: true,
-			update: {
-				...updates[0],
-				operations: operations.slice(0, split),
-			},
-		});
 		calculation.cancel();
 		currentWorker().emit({ type: 'result', outcome: cancelled });
 		currentWorker().emit({ type: 'result', outcome: cancelled.incumbent });
@@ -336,29 +312,14 @@ describe('user cancellation', () => {
 			explanationError: { code: 'explanation-error', message: 'Unavailable' },
 		});
 		currentWorker().emit({
-			type: 'trace-update',
+			type: 'artifacts',
-			totalMs: 0,
-			acknowledge: true,
-			update: {
-				operations: operations.slice(split),
-			},
-		});
-		const trace = artifacts.trace;
-		currentWorker().emit({
-			type: 'artifacts-start',
 			artifacts: {},
-			trace: {
-				status: trace.status,
-				initialState: trace.initialState,
-				completedStages: trace.completedStages,
-				nonWorkingDates: trace.nonWorkingDates,
-				error: trace.error,
-			},
 		});
-		currentWorker().emit({ type: 'artifacts-complete' });
 		expect(await calculation.outcome).toEqual({ ...cancelled, calculationDate: '2024-01-01' });
 		expect(await calculation.explanationError).toMatchObject({ code: 'explanation-error' });
-		expect(await calculation.trace).toEqual(trace);
+		expect(currentWorker().terminate).toHaveBeenCalledOnce();
+		expect(currentWorker().postMessage).toHaveBeenCalledTimes(2);
+		expect(artifacts.finalState?.placements).toEqual(cancelled.incumbent.placements);
 	});
 
 	it.each([false, true])(
@@ -399,7 +360,6 @@ describe('user cancellation', () => {
 			kind: 'PlanningIncomplete',
 			reasons: [{ code: 'worker-error' }],
 		});
-		expect((await calculation.trace)?.status).toBe('failed');
 	});
 
 	it('keeps a cancellation accepted before a queued completion and adapts its explanation without replay', async () => {
@@ -424,7 +384,6 @@ describe('user cancellation', () => {
 			kind: 'PlanExplanation',
 			incomplete: { reason: { code: 'user-cancelled' } },
 		});
-		expect((await calculation.trace)?.status).toBe('incomplete');
 		expect(currentWorker().postMessage).toHaveBeenCalledTimes(2);
 	});
 
@@ -453,7 +412,6 @@ describe('user cancellation', () => {
 		currentWorker().emit({ type: 'result', outcome });
 		currentWorker().emit({ type: 'artifacts', artifacts: {} });
 		expect(await newer.outcome).toEqual({ ...outcome, calculationDate: '2024-01-01' });
-		await newer.trace;
 		const sent = currentWorker().postMessage.mock.calls.length;
 		newer.cancel();
 		expect(currentWorker().postMessage).toHaveBeenCalledTimes(sent);

src/app/services/leave-planner-explanation.spec.ts

@@ -1,6 +1,6 @@
 import { createOptimizationPresetRules } from './rule-service';
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
-import { createPlanningCalculation, applyReplayDeltas } from './leave-planner.service';
+import { createPlanningCalculation } from './leave-planner.service';
 
 const balance = (
 	id: string,
@@ -18,8 +18,92 @@ afterEach(() => vi.useRealTimers());
 
 const presets = createOptimizationPresetRules();
 
-describe('planner explanation and trace seam', () => {
+describe('planner explanation and alternative dates', () => {
-	it('replays a reported occurrence without borrowing its future balance from the final plan', async () => {
+	it('delivers only the displayed plan, explanation and state needed for alternative dates', async () => {
+		const calculation = createPlanningCalculation({
+			horizon: { start: '2024-01-02', end: '2024-01-10' },
+			balances: [balance('cp', 'cp', 1, '2024-01-09')],
+			rules: [presets[0]],
+		});
+		const outcome = await calculation.outcome;
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
+		expect(Object.keys(calculation).sort()).toEqual([
+			'analyzeCounterfactual',
+			'cancel',
+			'explanation',
+			'explanationError',
+			'id',
+			'outcome',
+			'snapshot',
+			'timings',
+		]);
+		const core = await import('./leave-planner.core');
+		let artifacts: import('./leave-planner.core').PlanningArtifacts = {};
+		expect(
+			core.calculatePlanningInternal(
+				calculation.snapshot,
+				undefined,
+				(value) => (artifacts = value),
+			),
+		).toEqual(outcome);
+		expect(Object.keys(artifacts).sort()).toEqual([
+			'explanation',
+			'explanationError',
+			'finalState',
+			'timings',
+		]);
+		expect(artifacts.finalState?.placements).toEqual(outcome.placements);
+		expect(Object.keys(artifacts.timings ?? {})).toEqual(['planningWorkMs']);
+		const original = structuredClone(outcome);
+		const analysis = await calculation.analyzeCounterfactual(outcome.placements[0]);
+		expect(analysis.results).toHaveLength(8);
+		for (const result of analysis.results) {
+			expect(result).not.toHaveProperty('historicalStatus');
+			expect(result).not.toHaveProperty('historicalReason');
+		}
+		expect(outcome).toEqual(original);
+	});
+
+	it('excludes observers from the technical budget and keeps the outcome after explanation delivery fails', async () => {
+		const core = await import('./leave-planner.core');
+		let elapsed = 0;
+		const clock = vi.spyOn(performance, 'now').mockImplementation(() => elapsed);
+		let delivered = false;
+		let artifacts: import('./leave-planner.core').PlanningArtifacts = {};
+		try {
+			const outcome = core.calculatePlanningInternal(
+				{
+					horizon: { start: '2024-01-02', end: '2024-01-10' },
+					balances: [],
+					rules: [],
+					deadlineMs: 10,
+					progress: () => (elapsed += 100),
+				},
+				() => (elapsed += 500),
+				(value) => (artifacts = value),
+				() => (delivered = true),
+				() => {
+					expect(delivered).toBe(true);
+					elapsed += 1000;
+					throw new Error('Explanation delivery failed.');
+				},
+			);
+			expect(outcome.kind).toBe('Plan');
+			expect(artifacts.explanationError).toMatchObject({
+				code: 'explanation-error',
+				message: 'Explanation delivery failed.',
+			});
+			expect(artifacts.finalState?.horizon).toEqual({
+				start: '2024-01-02',
+				end: '2024-01-10',
+			});
+			expect(artifacts.timings?.planningWorkMs).toBe(0);
+		} finally {
+			clock.mockRestore();
+		}
+	});
+
+	it('keeps earned availability after a reported occurrence is extended', async () => {
 		vi.setSystemTime(new Date('2024-05-03T12:00:00Z'));
 		const core = await import('./leave-planner.core');
 		let artifacts: import('./leave-planner.core').PlanningArtifacts = {};
@@ -67,42 +151,25 @@ describe('planner explanation and trace seam', () => {
 			undefined,
 			(value) => (artifacts = value),
 		);
-		if (outcome.kind !== 'Plan' || !artifacts.trace || !artifacts.finalState)
+		if (outcome.kind !== 'Plan' || !artifacts.finalState)
-			throw new Error('Expected the extended generator to finance a traced plan.');
+			throw new Error('Expected the extended generator to finance a plan.');
-		const replay = {
-			balances: artifacts.trace.initialState.balances.map((item) => ({ ...item })),
-			placements: new Map(
-				artifacts.trace.initialState.placements.map((item) => [item.date, item]),
-			),
-			earnedActivations: [...artifacts.trace.initialState.earnedActivations],
-		};
 		const earnedId = 'earned:producer:2024-05-01';
-		let recognized = false;
+		expect(artifacts.finalState.balances).toContainEqual(
-		for (const decision of artifacts.trace.phases.flatMap(({ decisions }) => decisions)) {
+			expect.objectContaining({
-			applyReplayDeltas(replay, decision.deltas, artifacts.finalState);
+				id: earnedId,
-			if (
-				decision.deltas.some(
-					({ kind, balanceId }) => kind === 'earned-activated' && balanceId === earnedId,
-				)
-			) {
-				recognized = true;
-				expect(replay.earnedActivations.map(({ id }) => id)).toContain(earnedId);
-				expect(replay.balances.map(({ id }) => id)).not.toContain(earnedId);
-			}
-		}
-		expect(recognized).toBe(true);
-		expect(replay.balances).toEqual(artifacts.finalState.balances);
-		expect([...replay.placements.values()]).toEqual(artifacts.finalState.placements);
-		expect(replay.earnedActivations).toEqual(artifacts.finalState.earnedActivations);
-		expect(replay.balances.find(({ id }) => id === earnedId)).toMatchObject({
-			remaining: 0,
 				availableFrom: '2024-05-06',
 				expiryDate: '2025-05-06',
-		});
+				remaining: 0,
+			}),
+		);
+		expect(outcome.placements.find(({ balanceId }) => balanceId === earnedId)?.date).toBe(
+			'2024-05-07',
+		);
+		expect(artifacts.finalState.placements).toEqual(outcome.placements);
 	});
 
 	it.each([5, 8])(
-		'keeps %s unrelated obligation branches linear when a declared entitlement is already reported',
+		'keeps %s unrelated obligations valid without duplicating a reported entitlement',
 		async (count) => {
 			vi.setSystemTime(new Date('2024-05-06T12:00:00Z'));
 			const core = await import('./leave-planner.core');
@@ -116,11 +183,8 @@ describe('planner explanation and trace seam', () => {
 				'2024-04-25',
 				'2024-04-26',
 			].slice(0, count);
-			const branchCounts: number[] = [];
 			for (const rewardDays of [0, 1]) {
-				let artifacts: import('./leave-planner.core').PlanningArtifacts = {};
+				const outcome = core.calculatePlanningInternal({
-				const outcome = core.calculatePlanningInternal(
-					{
 					horizon: { start: '2024-04-17', end: '2024-05-08' },
 					declaredDays: [
 						{ date: '2024-04-29', type: 'cp' },
@@ -157,33 +221,20 @@ describe('planner explanation and trace seam', () => {
 							rewardType: 'other',
 						},
 					],
-					},
+				});
-					undefined,
+				if (outcome.kind !== 'Plan') throw new Error('Expected a completed plan.');
-					(value) => (artifacts = value),
-				);
-				if (outcome.kind !== 'Plan' || !artifacts.trace)
-					throw new Error('Expected a traced completed plan.');
 				expect(outcome.placements.map(({ date }) => date)).toEqual(dates);
 				expect(outcome.remainingBalances).toEqual([]);
-				branchCounts.push(
-					artifacts.trace.phases
-						.find(({ name }) => name === 'obligations')
-						?.decisions.filter(({ deltas }) =>
-							deltas.some(({ placement }) => placement !== undefined),
-						).length ?? 0,
-				);
 				if (rewardDays)
 					expect(outcome.ifThenContributions?.[0].earnedEntitlement).toMatchObject({
 						availableFrom: '2024-05-02',
 						added: false,
 					});
 			}
-			expect(branchCounts[0]).toBeGreaterThan(0);
-			expect(branchCounts[1]).toBe(branchCounts[0]);
 		},
 	);
 
-	it('replays an already-reported entitlement without inventing a transient earned balance under explicit priorities', async () => {
+	it('keeps reported entitlements out of the final state under explicit priorities', async () => {
 		vi.setSystemTime(new Date('2024-05-06T12:00:00Z'));
 		const core = await import('./leave-planner.core');
 		let artifacts: import('./leave-planner.core').PlanningArtifacts = {};
@@ -224,69 +275,17 @@ describe('planner explanation and trace seam', () => {
 			undefined,
 			(value) => (artifacts = value),
 		);
-		if (outcome.kind !== 'Plan' || !artifacts.trace || !artifacts.finalState)
+		if (outcome.kind !== 'Plan' || !artifacts.finalState)
-			throw new Error('Expected a traced completed plan.');
+			throw new Error('Expected a completed plan.');
 		expect(outcome.placements).toMatchObject([{ date: '2024-05-07', balanceId: 'cp' }]);
 		expect(outcome.remainingBalances).toEqual([]);
 		expect(outcome.ifThenContributions?.[0].earnedEntitlement).toMatchObject({
 			availableFrom: '2024-05-06',
 			added: false,
 		});
-		const decisions = artifacts.trace.phases.flatMap(({ decisions }) => decisions);
-		const deltas = decisions.flatMap(({ deltas }) => deltas);
-		expect(deltas).toContainEqual(
-			expect.objectContaining({ kind: 'balance-changed', balanceId: 'cp' }),
-		);
-		expect(deltas).not.toContainEqual(
-			expect.objectContaining({
-				kind: 'balance-changed',
-				balanceId: 'earned:producer:2024-05-01',
-			}),
-		);
-		const initial = artifacts.trace.initialState;
-		const replay = {
-			balances: initial.balances.map((balance) => ({ ...balance })),
-			placements: new Map(
-				initial.placements.map((placement) => [
-					placement.date,
-					{ ...placement, ruleIds: [...placement.ruleIds] },
-				]),
-			),
-			earnedActivations: initial.earnedActivations.map((activation) => ({
-				...activation,
-				dates: [...activation.dates],
-			})),
-		};
-		for (const decision of decisions) applyReplayDeltas(replay, decision.deltas);
-		expect(replay.balances).toEqual(artifacts.finalState.balances);
-		expect(replay.earnedActivations).toEqual(artifacts.finalState.earnedActivations);
-		expect([...replay.placements.values()]).toEqual(outcome.placements);
 	});
 
-	it('records only actual evaluations and publishes non-working dates as metadata', async () => {
+	it('associates every joint obligation with its shared placement', async () => {
-		const calculation = createPlanningCalculation({
-			horizon: { start: '2024-01-01', end: '2024-01-07' },
-			balances: [],
-			rules: [],
-		});
-		const outcome = await calculation.outcome;
-		const trace = await calculation.trace;
-
-		expect(outcome.kind).toBe('Plan');
-		expect(trace?.status).toBe('ready');
-		expect(trace?.nonWorkingDates?.map(({ date }) => date)).toEqual([
-			'2024-01-01',
-			'2024-01-06',
-		]);
-		expect(
-			trace?.phases
-				.flatMap((phase) => phase.decisions)
-				.flatMap((decision) => decision.candidates),
-		).toEqual([]);
-		expect(trace?.phases.every((phase) => phase.status === 'completed')).toBe(true);
-	});
-
-	it('keeps joint obligation branches atomic and associates the selected shared placement', async () => {
 		const calculation = createPlanningCalculation({
 			horizon: { start: '2024-01-01', end: '2024-01-08' },
 			balances: [balance('cp', 'cp', 2, '2024-12-31')],
@@ -312,151 +311,13 @@ describe('planner explanation and trace seam', () => {
 			],
 		});
 		const outcome = await calculation.outcome;
-		const trace = await calculation.trace;
 		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan' || !trace) return;
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
-
-		const obligations = trace.phases.find((phase) => phase.name === 'obligations');
-		const branch = obligations?.decisions
-			.flatMap((decision) => decision.candidates)
-			.find((candidate) => candidate.status === 'chosen' && candidate.dates?.length === 2);
-		expect(branch?.dates).toHaveLength(2);
-		expect(
-			branch?.dates?.every((date) => outcome.placements.some((item) => item.date === date)),
-		).toBe(true);
 		const sharedPlacement = outcome.placements.find(
 			(placement) =>
 				placement.ruleIds.includes('joint') && placement.ruleIds.includes('shared'),
 		);
 		expect(sharedPlacement).toBeDefined();
-		const acceptedMutation = obligations?.decisions.find((decision) =>
-			decision.deltas.some(
-				(delta) =>
-					(delta.kind === 'placement-added' || delta.kind === 'placement-updated') &&
-					delta.placement !== undefined &&
-					delta.placement.date === sharedPlacement?.date &&
-					delta.placement.ruleIds.includes('joint') &&
-					delta.placement.ruleIds.includes('shared'),
-			),
-		);
-		expect(acceptedMutation).toBeDefined();
-		expect(acceptedMutation?.branch?.deltas).toContainEqual(
-			expect.objectContaining({
-				kind: 'placement-updated',
-				placement: expect.objectContaining({
-					date: sharedPlacement?.date,
-					ruleIds: ['joint', 'shared'],
-				}),
-			}),
-		);
-		const sameDatesOnRejectedParent = obligations?.decisions.filter(
-			(decision) =>
-				decision.id !== acceptedMutation?.id &&
-				decision.candidates.some(
-					(candidate) =>
-						candidate.status === 'evaluated-rejected' &&
-						candidate.dates?.includes(sharedPlacement?.date ?? ''),
-				),
-		);
-		expect(
-			sameDatesOnRejectedParent?.some((decision) => decision.branch?.parentDecisionId),
-		).toBe(true);
-	});
-
-	it('records at-risk assignments as sequential decisions with exact prior-state deltas', async () => {
-		const calculation = createPlanningCalculation({
-			horizon: { start: '2024-01-01', end: '2024-01-08' },
-			balances: [balance('cp', 'cp', 2, '2024-01-07')],
-			rules: [presets[0]],
-		});
-		const outcome = await calculation.outcome;
-		const trace = await calculation.trace;
-		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan' || !trace) return;
-
-		const atRisk = trace.phases.find(
-			(phase) => phase.name === 'optimization:default-unplaced-at-risk',
-		);
-		const jan2 = atRisk?.decisions.find((decision) =>
-			decision.deltas.some(
-				(delta) => delta.kind === 'placement-added' && delta.date === '2024-01-02',
-			),
-		);
-		const jan3 = atRisk?.decisions.find((decision) =>
-			decision.deltas.some(
-				(delta) => delta.kind === 'placement-added' && delta.date === '2024-01-03',
-			),
-		);
-		expect(jan2?.candidates.some((candidate) => candidate.status === 'chosen')).toBe(true);
-		expect(jan2?.candidates.find((candidate) => candidate.status === 'chosen')).toMatchObject({
-			technicalComparison: [
-				{ name: 'obligation-validity', direction: 'minimize', before: 0, after: 0 },
-				{
-					name: `optimization:${presets[0].id}`,
-					direction: 'minimize',
-					before: 2,
-					after: 1,
-				},
-			],
-			firstDecisiveComparator: `optimization:${presets[0].id}`,
-		});
-		expect(jan2?.deltas).toContainEqual(
-			expect.objectContaining({
-				kind: 'balance-changed',
-				remainingBefore: 2,
-				remainingAfter: 1,
-			}),
-		);
-		expect(jan3?.candidates.some((candidate) => candidate.status === 'chosen')).toBe(true);
-		expect(jan3?.candidates.find((candidate) => candidate.status === 'chosen')).toMatchObject({
-			technicalComparison: [
-				{ name: 'obligation-validity', direction: 'minimize', before: 0, after: 0 },
-				{
-					name: `optimization:${presets[0].id}`,
-					direction: 'minimize',
-					before: 1,
-					after: 0,
-				},
-			],
-			firstDecisiveComparator: `optimization:${presets[0].id}`,
-		});
-		expect(jan3?.deltas).toContainEqual(
-			expect.objectContaining({
-				kind: 'balance-changed',
-				remainingBefore: 1,
-				remainingAfter: 0,
-			}),
-		);
-		for (const [date, decision] of [
-			['2024-01-02', jan2],
-			['2024-01-03', jan3],
-		] as const) {
-			expect(
-				decision?.candidates.filter(
-					(candidate) => candidate.status === 'chosen' && candidate.date === date,
-				),
-			).toHaveLength(1);
-			expect(
-				decision?.deltas.filter(
-					(delta) => delta.kind === 'placement-added' && delta.date === date,
-				),
-			).toHaveLength(1);
-		}
-		const selected = jan3?.deltas.find(
-			(delta) => delta.kind === 'placement-added' && delta.date === '2024-01-03',
-		)?.placement;
-		expect(selected).toBeDefined();
-		if (!jan3 || !selected) return;
-		const analysis = await calculation.analyzeCounterfactual({
-			decisionId: jan3.id,
-			placement: selected,
-		});
-		expect(analysis.kind).toBe('Counterfactual');
-		if (analysis.kind === 'Counterfactual')
-			expect(analysis.results.find((item) => item.date === '2024-01-02')).toMatchObject({
-				status: 'ineligible',
-				reason: { code: 'occupied' },
-			});
 	});
 
 	it('puts actual obligation validity first in stable plan explanations', async () => {
@@ -478,6 +339,7 @@ describe('planner explanation and trace seam', () => {
 		const outcome = await calculation.outcome;
 		const explanation = await calculation.explanation;
 		expect(outcome.kind).toBe('Plan');
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
 		expect(explanation?.kind).toBe('PlanExplanation');
 		if (explanation?.kind !== 'PlanExplanation') return;
 
@@ -498,7 +360,7 @@ describe('planner explanation and trace seam', () => {
 		expect(placement.firstDecisiveObjective).toBe('obligation-validity');
 	});
 
-	it('records the balance order used for a shared ANY preference placement', async () => {
+	it('uses the earlier-expiring balance for shared ANY preferences', async () => {
 		const calculation = createPlanningCalculation({
 			horizon: { start: '2024-01-01', end: '2024-01-08' },
 			balances: [
@@ -528,9 +390,8 @@ describe('planner explanation and trace seam', () => {
 			],
 		});
 		const outcome = await calculation.outcome;
-		const trace = await calculation.trace;
 		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan' || !trace) return;
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
 
 		const sharedPlacement = outcome.placements.find((placement) =>
 			placement.ruleIds.includes('any-preference'),
@@ -540,116 +401,9 @@ describe('planner explanation and trace seam', () => {
 			balanceId: 'rtt-first',
 			ruleIds: ['any-preference', 'rtt-preference'],
 		});
-		const candidate = trace.phases
-			.find((phase) => phase.name === 'preference:any-preference')
-			?.decisions.flatMap((decision) => decision.candidates)
-			.find((item) => item.status === 'chosen' && item.date === '2024-01-03');
-		expect(candidate).toMatchObject({
-			firstDecisiveComparator: 'preference:rtt-preference',
-			placement: expect.objectContaining({ balanceId: 'rtt-first' }),
-		});
-		const compared = trace.phases
-			.find((phase) => phase.name === 'preference:any-preference')
-			?.decisions.flatMap((decision) => decision.candidates);
-		expect(compared).toContainEqual(
-			expect.objectContaining({
-				status: 'evaluated-rejected',
-				placement: expect.objectContaining({ balanceId: 'rtt-second' }),
-				technicalComparison: expect.arrayContaining([
-					{
-						name: 'preference:any-preference',
-						direction: 'maximize',
-						before: 1,
-						after: 1,
-					},
-					{
-						name: 'preference:rtt-preference',
-						direction: 'maximize',
-						before: 1,
-						after: 1,
-					},
-					{
-						name: 'balance-expiry',
-						direction: 'minimize',
-						before: '2025-01-05',
-						after: '2025-01-06',
-					},
-				]),
-				firstDecisiveComparator: 'balance-expiry',
-			}),
-		);
 	});
 
-	it('records actual IfThen leaf comparisons and selected branch identity', async () => {
+	it('keeps an earned obligation entitlement and its consumer chronological', async () => {
-		const calculation = createPlanningCalculation({
-			horizon: { start: '2024-01-01', end: '2025-01-01' },
-			balances: [balance('cp', 'cp', 2, '2024-12-31')],
-			rules: [
-				{
-					id: 'if-then-preference',
-					type: 'if_then',
-					force: 'preference',
-					dayOfWeek: 3,
-					placeDays: 1,
-					placeType: 'cp',
-					placement: 'auto',
-					rewardDays: 0,
-				},
-			],
-		});
-		const outcome = await calculation.outcome;
-		const trace = await calculation.trace;
-		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan' || !trace) return;
-
-		const candidates = trace.phases
-			.flatMap((phase) => phase.decisions)
-			.flatMap((decision) =>
-				decision.candidates
-					.filter((candidate) =>
-						candidate.technicalComparison?.some(
-							(item) => item.name === 'preference:if-then-preference',
-						),
-					)
-					.map((candidate) => ({ candidate, decision })),
-			);
-		const chosen = candidates.find(({ candidate }) => candidate.status === 'chosen');
-		const preferenceLeaves =
-			trace.phases
-				.find((phase) => phase.name === 'preference:if-then-preference')
-				?.decisions.flatMap((decision) => decision.candidates)
-				.filter((candidate) =>
-					candidate.technicalComparison?.some(
-						(item) => item.name === 'preference:if-then-preference',
-					),
-				) ?? [];
-		expect(preferenceLeaves.length).toBeGreaterThan(1);
-		expect(preferenceLeaves.some((candidate) => candidate.status === 'chosen')).toBe(true);
-		expect(
-			preferenceLeaves.some((candidate) => candidate.status === 'evaluated-rejected'),
-		).toBe(true);
-		expect(candidates.some(({ candidate }) => candidate.status === 'evaluated-rejected')).toBe(
-			true,
-		);
-		expect(chosen?.candidate.technicalComparison).toEqual(
-			expect.arrayContaining([
-				expect.objectContaining({
-					name: 'preference:if-then-preference',
-					direction: 'maximize',
-				}),
-			]),
-		);
-		expect(
-			(chosen?.decision.branch?.deltas ?? chosen?.decision.deltas ?? []).length,
-		).toBeGreaterThan(0);
-		expect(
-			chosen?.candidate.dates?.every((date) =>
-				outcome.placements.some((p) => p.date === date),
-			),
-		).toBe(true);
-	});
-
-	it('records earned obligation branches with the activated entitlement and its consumer', async () => {
 		const calculation = createPlanningCalculation({
 			horizon: { start: '2024-04-25', end: '2024-05-08' },
 			balances: [
@@ -680,29 +434,13 @@ describe('planner explanation and trace seam', () => {
 			],
 		});
 		const outcome = await calculation.outcome;
-		const trace = await calculation.trace;
 		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan' || !trace) return;
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
 
 		const earned = outcome.placements.find((placement) =>
 			placement.balanceId.startsWith('earned:'),
 		);
 		expect(earned?.ruleIds).toContain('consumer');
-		const decisions = trace.phases.flatMap((phase) => phase.decisions);
-		const activation = decisions
-			.flatMap((decision) => decision.deltas)
-			.find(
-				(delta) =>
-					delta.kind === 'earned-activated' && delta.balanceId === earned?.balanceId,
-			);
-		expect(activation?.activation).toMatchObject({ ruleId: 'producer', dates: ['2024-05-02'] });
-		const branch = decisions
-			.flatMap((decision) => decision.candidates)
-			.find(
-				(candidate) =>
-					candidate.status === 'chosen' && candidate.dates?.includes(earned?.date ?? ''),
-			);
-		expect(branch).toBeDefined();
 	});
 
 	it('rejects a producer move that delays its earned entitlement past the consumer', async () => {
@@ -737,7 +475,7 @@ describe('planner explanation and trace seam', () => {
 		});
 		const outcome = await calculation.outcome;
 		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan') return;
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
 		const producer = outcome.placements.find((placement) =>
 			placement.ruleIds.includes('producer'),
 		);
@@ -802,7 +540,7 @@ describe('planner explanation and trace seam', () => {
 		});
 		const outcome = await calculation.outcome;
 		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan') return;
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
 		const atRisk = outcome.placements.find(
 			(placement) =>
 				placement.balanceId === 'cp2' &&
@@ -823,7 +561,7 @@ describe('planner explanation and trace seam', () => {
 		).toBeUndefined();
 	});
 
-	it('records earned balance availability metadata changes when a shared period extends', async () => {
+	it('keeps earned balance metadata consistent when a shared period extends', async () => {
 		const calculation = createPlanningCalculation({
 			horizon: { start: '2024-04-25', end: '2024-05-15' },
 			balances: [
@@ -863,30 +601,13 @@ describe('planner explanation and trace seam', () => {
 			],
 		});
 		const outcome = await calculation.outcome;
-		const trace = await calculation.trace;
 		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan' || !trace) return;
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
 
 		const earnedBalanceId = outcome.placements.find((placement) =>
 			placement.ruleIds.includes('rtt-preference'),
 		)?.balanceId;
 		expect(earnedBalanceId).toBeDefined();
-		const changes = trace.phases
-			.flatMap((phase) => phase.decisions)
-			.flatMap((decision) => decision.deltas)
-			.filter(
-				(delta) => delta.kind === 'balance-changed' && delta.balanceId === earnedBalanceId,
-			);
-		expect(changes).toContainEqual(
-			expect.objectContaining({
-				remainingBefore: 1,
-				remainingAfter: 1,
-				balance: expect.objectContaining({
-					availableFrom: '2024-05-06',
-					expiryDate: '2025-05-06',
-				}),
-			}),
-		);
 	});
 
 	it('compares every horizon date while preserving the selected placement provenance', async () => {
@@ -907,7 +628,7 @@ describe('planner explanation and trace seam', () => {
 		});
 		const outcome = await calculation.outcome;
 		expect(outcome.kind).toBe('Plan');
-		if (outcome.kind !== 'Plan') return;
+		if (outcome.kind !== 'Plan') throw new Error('Expected a plan.');
 		const selected = outcome.placements.find((placement) =>
 			placement.ruleIds.includes('exact-date'),
 		);
@@ -1022,27 +743,6 @@ describe('planner explanation and trace seam', () => {
 			if (outcome.kind !== 'PlanningConflict') continue;
 			expect(outcome.reasons[0].code).toBe(conflictCodes[index]);
 			expect((await calculation.explanation)?.kind).toBe('ConflictExplanation');
-			const trace = await calculation.trace;
-			expect(trace?.phases.some((phase) => phase.name === 'obligations')).toBe(true);
-			expect(
-				trace?.phases.some(
-					(phase) => phase.name === 'optimization:default-holiday-week-value',
-				),
-			).toBe(false);
-			if (index === 1)
-				expect(
-					trace?.phases
-						.find((phase) => phase.name === 'obligations')
-						?.decisions.flatMap((decision) => decision.candidates).length,
-				).toBeGreaterThan(0);
-			if (index === 2)
-				expect(
-					trace?.phases
-						.find((phase) => phase.name === 'obligations')
-						?.decisions.some((decision) =>
-							decision.candidates.some((candidate) => candidate.dates?.length),
-						),
-				).toBe(true);
 		}
 
 		const invalid = createPlanningCalculation({
@@ -1052,7 +752,6 @@ describe('planner explanation and trace seam', () => {
 		});
 		expect((await invalid.outcome).kind).toBe('InvalidInput');
 		expect(await invalid.explanation).toBeUndefined();
-		expect(await invalid.trace).toBeUndefined();
 	});
 
 	it('does not classify a joint-date conflict as earned when only a preference generates leave', async () => {
@@ -1094,7 +793,7 @@ describe('planner explanation and trace seam', () => {
 	it('recovers an incumbent explanation from the exact delivered checkpoint state', async () => {
 		const core = await import('./leave-planner.core');
 		let checkpointPlan: import('./leave-planner.core').PlanOutcome | undefined;
-		let checkpointState: import('./leave-planner.core').PlanningTraceState | undefined;
+		let checkpointState: import('./leave-planner.core').PlanningStateSnapshot | undefined;
 		const request = {
 			horizon: { start: '2024-01-01', end: '2024-01-10' },
 			balances: [balance('cp', 'cp', 2, '2024-01-31')],
@@ -1124,7 +823,7 @@ describe('planner explanation and trace seam', () => {
 		expect(recovered.explanation.incomplete?.reason.code).toBe('worker-error');
 		expect(recovered.explanation.placements).toHaveLength(checkpointPlan.placements.length);
 
-		let completedState: import('./leave-planner.core').PlanningTraceState | undefined;
+		let completedState: import('./leave-planner.core').PlanningStateSnapshot | undefined;
 		const completed = core.calculatePlanningInternal(
 			{ ...request, progress: undefined },
 			(plan, state) => {
@@ -1144,116 +843,7 @@ describe('planner explanation and trace seam', () => {
 			expect(completedRecovery.explanation.incomplete).toBeUndefined();
 	});
 
-	it('does not charge a deliberately slow incremental trace consumer to planning work', async () => {
+	it('explains incomplete calculations before and after a valid plan', async () => {
-		const core = await import('./leave-planner.core');
-		let clock = 0;
-		vi.stubGlobal('performance', { now: () => ++clock });
-		const request = {
-			horizon: { start: '2024-01-01', end: '2024-01-15' },
-			balances: [balance('cp', 'cp', 3, '2024-01-31')],
-			rules: presets,
-			deadlineMs: 100_000,
-		};
-		const plain = core.calculatePlanningInternal(request);
-		clock = 0;
-		let callbackCount = 0;
-		let artifacts: import('./leave-planner.core').PlanningArtifacts | undefined;
-		const operations: import('./leave-planner.core').PlanningTraceOperation[] = [];
-		const traced = core.calculatePlanningInternal(
-			{
-				...request,
-				traceProgress: (
-					_totalMs: number,
-					update: import('./leave-planner.core').PlanningTraceUpdate,
-				) => {
-					callbackCount++;
-					clock += 10_000;
-					operations.push(...update.operations);
-				},
-			},
-			undefined,
-			(value) => (artifacts = value),
-		);
-		expect(traced).toEqual(plain);
-		expect(callbackCount).toBeGreaterThan(0);
-		expect(artifacts?.trace?.status).toBe('ready');
-		expect(artifacts?.timings?.planningWorkMs).toBeLessThan(request.deadlineMs);
-		expect(artifacts?.timings?.traceTransferMs).toBeGreaterThanOrEqual(callbackCount * 10_000);
-		expect(artifacts?.timings?.traceTransferMs).toBeGreaterThan(request.deadlineMs);
-		const decisions = artifacts?.trace?.phases.flatMap((phase) => phase.decisions) ?? [];
-		const candidateUpdates = operations.filter((operation) => operation.kind === 'candidate');
-		expect(candidateUpdates.some((operation) => operation.mode === 'replace')).toBe(true);
-		const streamedCandidates = new Map<string, unknown>();
-		for (const operation of candidateUpdates)
-			if (operation.kind === 'candidate')
-				streamedCandidates.set(
-					`${operation.phaseId}/${operation.decisionId}/${operation.index}`,
-					operation.candidate,
-				);
-		expect(streamedCandidates.size).toBe(
-			decisions.flatMap((decision) => decision.candidates).length,
-		);
-		expect(operations.filter((operation) => operation.kind === 'delta')).toHaveLength(
-			decisions.flatMap((decision) => decision.deltas).length,
-		);
-	});
-
-	it('coalesces pending candidate snapshots without losing later flushed replacements', async () => {
-		const core = await import('./leave-planner.core');
-		vi.stubGlobal('performance', { now: () => 0 });
-		const request = {
-			horizon: { start: '2024-01-01', end: '2024-01-08' },
-			balances: [balance('cp', 'cp', 2, '2024-01-07')],
-			rules: [presets[0]],
-		};
-		let plainArtifacts: import('./leave-planner.core').PlanningArtifacts | undefined;
-		const plain = core.calculatePlanningInternal(request, undefined, (value) => {
-			plainArtifacts = value;
-		});
-		const operations: import('./leave-planner.core').PlanningTraceOperation[] = [];
-		let streamedArtifacts: import('./leave-planner.core').PlanningArtifacts | undefined;
-		const streamed = core.calculatePlanningInternal(
-			{
-				...request,
-				traceProgress: (
-					_totalMs: number,
-					update: import('./leave-planner.core').PlanningTraceUpdate,
-				) => operations.push(...update.operations),
-			},
-			undefined,
-			(value) => (streamedArtifacts = value),
-		);
-
-		expect(streamed).toEqual(plain);
-		expect(streamedArtifacts?.trace).toEqual(plainArtifacts?.trace);
-		const decisions =
-			streamedArtifacts?.trace?.phases.flatMap((phase) => phase.decisions) ?? [];
-		const candidates = decisions.flatMap((decision) =>
-			decision.candidates.map((candidate, index) => ({
-				key: `${decision.id}/${index}`,
-				candidate,
-			})),
-		);
-		expect(candidates.length).toBeGreaterThan(0);
-		const candidateOperations = operations.filter(
-			(operation): operation is Extract<typeof operation, { kind: 'candidate' }> =>
-				operation.kind === 'candidate',
-		);
-		expect(candidateOperations).toHaveLength(candidates.length);
-		const finalStreamedCandidates = new Map(
-			candidateOperations.map((operation) => [
-				`${operation.decisionId}/${operation.index}`,
-				operation,
-			]),
-		);
-		for (const { key, candidate } of candidates) {
-			expect(finalStreamedCandidates.get(key)?.candidate).toEqual(candidate);
-			if (candidate.status === 'chosen')
-				expect(finalStreamedCandidates.get(key)?.mode).toBe('append');
-		}
-	});
-
-	it('reports matching completed, interrupted, and not-run phases at both interruption boundaries', async () => {
 		const early = createPlanningCalculation({
 			horizon: { start: '2024-01-01', end: '2024-01-10' },
 			balances: [balance('cp', 'cp', 1, '2024-01-31')],
@@ -1261,22 +851,9 @@ describe('planner explanation and trace seam', () => {
 			deadlineMs: 0,
 		});
 		const earlyOutcome = await early.outcome;
-		const earlyTrace = await early.trace;
 		expect(earlyOutcome.kind).toBe('PlanningIncomplete');
 		if (earlyOutcome.kind === 'PlanningIncomplete')
 			expect(earlyOutcome.completedStages).toEqual(['validation']);
-		expect(earlyTrace?.completedStages).toEqual(['validation']);
-		expect(earlyTrace?.phases.find((phase) => phase.name === 'validation')?.status).toBe(
-			'completed',
-		);
-		expect(earlyTrace?.phases.find((phase) => phase.name === 'obligations')?.status).toBe(
-			'interrupted',
-		);
-		expect(
-			earlyTrace?.phases.find(
-				(phase) => phase.name === 'optimization:default-unplaced-at-risk',
-			)?.status,
-		).toBe('not-run');
 
 		const quality = createPlanningCalculation({
 			horizon: { start: '2024-01-01', end: '2024-02-01' },
@@ -1289,7 +866,6 @@ describe('planner explanation and trace seam', () => {
 			},
 		});
 		const qualityOutcome = await quality.outcome;
-		const qualityTrace = await quality.trace;
 		expect(qualityOutcome.kind).toBe('PlanningIncomplete');
 		if (qualityOutcome.kind !== 'PlanningIncomplete') return;
 		expect(qualityOutcome.reasons[0].code).toBe('planner-error');
@@ -1298,16 +874,5 @@ describe('planner explanation and trace seam', () => {
 			'obligations',
 			'optimization:default-unplaced-at-risk',
 		]);
-		expect(qualityTrace?.completedStages).toEqual(qualityOutcome.completedStages);
-		expect(
-			qualityTrace?.phases.find(
-				(phase) => phase.name === 'optimization:default-holiday-week-value',
-			)?.status,
-		).toBe('interrupted');
-		expect(
-			qualityTrace?.phases.find(
-				(phase) => phase.name === 'optimization:default-non-working-day-gain',
-			)?.status,
-		).toBe('not-run');
 	});
 });

src/app/services/leave-planner-quality-trace.spec.ts

@@ -1,169 +0,0 @@
-import { createOptimizationPresetRules } from './rule-service';
-import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
-import { createPlanningCalculation } from './leave-planner.service';
-import {
-	calculatePlanningInternal,
-	type PlanningArtifacts,
-	type PlanningTraceCandidate,
-	type PlanningTraceUpdate,
-} from './leave-planner.core';
-import { OPTIMIZATION_PRESETS } from './planning-objectives';
-
-beforeEach(() => vi.stubGlobal('window', undefined));
-afterEach(() => vi.unstubAllGlobals());
-
-const presets = createOptimizationPresetRules();
-
-describe('quality calculation trace', () => {
-	it('keeps emitted comparison metadata unchanged when candidate snapshots are replaced', () => {
-		const updates: PlanningTraceUpdate[] = [];
-		const captured: string[] = [];
-		let artifacts: PlanningArtifacts = {};
-		let clock = 0;
-		const clockSpy = vi.spyOn(performance, 'now').mockImplementation(() => (clock += 30));
-		try {
-			const outcome = calculatePlanningInternal(
-				{
-					calculationDate: '2026-11-01',
-					horizon: { start: '2026-11-03', end: '2026-11-14' },
-					balances: [{ id: 'cp', type: 'cp', quantity: 2, expiryDate: '2027-01-01' }],
-					declaredDays: [
-						{ date: '2026-11-09', type: 'other' },
-						{ date: '2026-11-10', type: 'other' },
-					],
-					rules: [
-						{
-							id: 'holiday',
-							name: 'Holiday weeks',
-							type: 'optimization',
-							configuration: OPTIMIZATION_PRESETS.holidayWeekValue,
-						},
-						...[3, 5].map((thresholdDays) => ({
-							id: `deficit-${thresholdDays}`,
-							name: `Deficit ${thresholdDays} days`,
-							type: 'optimization',
-							configuration: {
-								...OPTIMIZATION_PRESETS.shortSequenceDeficit,
-								conditions: ['non-empty'],
-								thresholdDays,
-							},
-						})),
-					],
-					traceProgress: (_elapsed: number, update: PlanningTraceUpdate) => {
-						updates.push(update);
-						captured.push(JSON.stringify(update));
-					},
-				},
-				undefined,
-				(value) => (artifacts = value),
-			);
-			expect(outcome.kind).toBe('Plan');
-			expect(artifacts.trace?.status).toBe('ready');
-			expect(updates.map((update) => JSON.stringify(update))).toEqual(captured);
-			const emitted = new Map<string, PlanningTraceCandidate>();
-			let replacements = 0;
-			for (const update of updates)
-				for (const operation of update.operations) {
-					if (operation.kind !== 'candidate') continue;
-					if (operation.mode === 'replace') replacements++;
-					emitted.set(
-						`${operation.phaseId}/${operation.decisionId}/${operation.index}`,
-						operation.candidate,
-					);
-				}
-			expect(replacements).toBeGreaterThan(0);
-			expect(emitted.size).toBeGreaterThan(0);
-			for (const phase of artifacts.trace!.phases)
-				for (const decision of phase.decisions)
-					decision.candidates.forEach((candidate, index) =>
-						expect(emitted.get(`${phase.id}/${decision.id}/${index}`)).toEqual(
-							candidate,
-						),
-					);
-			const comparison = [...emitted.values()].find(
-				(candidate) => candidate.comparison,
-			)?.comparison;
-			expect(comparison?.after.objectives).toEqual(
-				expect.arrayContaining([
-					expect.objectContaining({
-						id: 'optimization:deficit-3',
-						label: 'Deficit 3 days',
-						direction: 'minimize',
-					}),
-					expect.objectContaining({
-						id: 'optimization:deficit-5',
-						label: 'Deficit 5 days',
-						direction: 'minimize',
-					}),
-				]),
-			);
-			expect(
-				[...emitted.values()].some(({ comparison }) => {
-					const values = comparison?.after.objectives;
-					return (
-						values?.find(({ id }) => id === 'optimization:deficit-3')?.value === 0 &&
-						values?.find(({ id }) => id === 'optimization:deficit-5')?.value === 1
-					);
-				}),
-			).toBe(true);
-		} finally {
-			clockSpy.mockRestore();
-		}
-	});
-
-	it('separates source effects from the actual incumbent comparison', async () => {
-		const calculation = createPlanningCalculation({
-			horizon: { start: '2024-01-01', end: '2024-02-01' },
-			balances: [
-				{
-					id: 'cp',
-					type: 'cp',
-					quantity: 2,
-					availableFrom: '2024-01-01',
-					expiryDate: '2024-01-31',
-				},
-			],
-			rules: presets,
-		});
-		expect((await calculation.outcome).kind).toBe('Plan');
-		const trace = await calculation.trace;
-		expect(trace?.status).toBe('ready');
-		const phase = trace?.phases.find(({ name }) => name === `optimization:${presets[0].id}`);
-		const decision = phase?.decisions.find(({ candidates }) =>
-			candidates.some(({ status, date }) => status === 'chosen' && date === '2024-01-02'),
-		);
-		const rejected = decision?.candidates.find(
-			({ date, comparison }) => date === '2024-01-05' && comparison,
-		);
-		expect(rejected?.status).toBe('evaluated-rejected');
-		const sourceValue = (state: 'before' | 'after', id: string) =>
-			rejected?.comparison?.[state].objectives.find((objective) => objective.id === id)
-				?.value;
-		expect(sourceValue('before', `optimization:${presets[0].id}`)).toBe(2);
-		expect(sourceValue('after', `optimization:${presets[0].id}`)).toBe(1);
-		expect(sourceValue('before', `optimization:${presets[2].id}`)).toBe(0);
-		expect(sourceValue('after', `optimization:${presets[2].id}`)).toBe(2);
-		expect(rejected?.comparison?.firstDecisiveObjective).toBe(`optimization:${presets[0].id}`);
-		// The January 2 candidate already gains three natural non-working days.
-		// January 5 improves its source state, but loses to that current best candidate.
-		expect(rejected?.technicalComparison).toContainEqual({
-			name: `optimization:${presets[2].id}`,
-			direction: 'maximize',
-			before: 3,
-			after: 2,
-		});
-		expect(
-			rejected?.technicalComparison?.some(
-				({ name }) => name === `optimization:${presets[3].id}`,
-			),
-		).toBe(false);
-		expect(rejected?.firstDecisiveComparator).toBe(`optimization:${presets[2].id}`);
-		expect(rejected?.reason?.message).toContain('did not improve the current best result');
-		expect(decision?.deltas).toContainEqual(
-			expect.objectContaining({
-				kind: 'placement-added',
-				date: '2024-01-02',
-			}),
-		);
-	});
-});

src/app/services/leave-planner-supporting-placements.spec.ts

@@ -6,10 +6,9 @@ import {
 	type PlanOutcome,
 	type PlanningArtifacts,
 	type PlanningRequest,
-	type PlanningTraceUpdate,
 } from './leave-planner.core';
 import { OPTIMIZATION_PRESETS } from './planning-objectives';
-import { applyReplayDeltas, createPlanningCalculation } from './leave-planner.service';
+import { createPlanningCalculation } from './leave-planner.service';
 
 const economy: OptimizationPlanningRule = {
 	id: 'economy',
@@ -415,9 +414,7 @@ describe('supporting placement economy and provenance', () => {
 	});
 
 	it('reclassifies a deferred support addition when an eligible earlier-expiring balance replaces it', () => {
-		let artifacts: PlanningArtifacts | undefined;
+		const outcome = calculatePlanningInternal({
-		const outcome = calculatePlanningInternal(
-			{
 			horizon: { start: '2024-05-06', end: '2024-05-11' },
 			balances: [
 				{ id: 'deferred', type: 'cp', quantity: 3, expiryDate: '2025-01-01' },
@@ -430,10 +427,7 @@ describe('supporting placement economy and provenance', () => {
 				},
 			],
 			rules: [bundles[0].rule, economy],
-			},
+		});
-			undefined,
-			(value) => (artifacts = value),
-		);
 		if (outcome.kind !== 'Plan') throw new Error('Expected a plan');
 		expect(
 			outcome.placements.map(({ date, balanceId, supporting }) => ({
@@ -448,20 +442,6 @@ describe('supporting placement economy and provenance', () => {
 		]);
 		expect(outcome.metrics.supportingPlacements).toBe(2);
 		expect(outcome.remainingBalances[0]).toMatchObject({ id: 'deferred', quantity: 1 });
-		expect(
-			artifacts?.trace?.phases.flatMap(({ decisions }) =>
-				decisions.flatMap(({ deltas }) => deltas),
-			),
-		).toContainEqual(
-			expect.objectContaining({
-				kind: 'placement-updated',
-				previousPlacement: expect.objectContaining({
-					balanceId: 'deferred',
-					supporting: true,
-				}),
-				placement: expect.objectContaining({ balanceId: 'at-risk', supporting: false }),
-			}),
-		);
 	});
 
 	it('compares new deferred support when at-risk holiday placements relocate into an explicit window', async () => {
@@ -491,13 +471,10 @@ describe('supporting placement economy and provenance', () => {
 		};
 		const economyFirst = plan({ ...request, rules: [holiday, economy, early] });
 		let artifacts: PlanningArtifacts | undefined;
-		const updates: { update: PlanningTraceUpdate; snapshot: string }[] = [];
 		const windowFirst = calculatePlanningInternal(
 			{
 				...request,
 				rules: [holiday, early, economy],
-				traceProgress: (_time: number, update: PlanningTraceUpdate) =>
-					updates.push({ update, snapshot: JSON.stringify(update) }),
 			},
 			(checkpoint, state) => expect(state?.placements).toEqual(checkpoint.placements),
 			(value) => (artifacts = value),
@@ -547,12 +524,8 @@ describe('supporting placement economy and provenance', () => {
 		expect(windowFirst.metrics.supportingPlacements).toBe(2);
 		expect(windowFirst.preferences[0].satisfied).toBe(2);
 		expect(windowFirst.metrics.holidayWeekValue).toBe(3);
-		if (
+		if (artifacts?.explanation?.kind !== 'PlanExplanation' || !artifacts.finalState)
-			artifacts?.explanation?.kind !== 'PlanExplanation' ||
+			throw new Error('Expected matching explanation and state snapshots');
-			!artifacts.finalState ||
-			!artifacts.trace
-		)
-			throw new Error('Expected matching explanation and trace artifacts');
 		expect(artifacts.finalState.placements).toEqual(windowFirst.placements);
 		expect(artifacts.explanation.placements.map(({ placement }) => placement)).toEqual(
 			windowFirst.placements,
@@ -568,33 +541,6 @@ describe('supporting placement economy and provenance', () => {
 				expect(placement.contributions).not.toContainEqual(contribution);
 			}
 		}
-		const replay = {
-			balances: artifacts.trace.initialState.balances.map((balance) => ({ ...balance })),
-			placements: new Map(
-				artifacts.trace.initialState.placements.map((placement) => [
-					placement.date,
-					placement,
-				]),
-			),
-			earnedActivations: [...artifacts.trace.initialState.earnedActivations],
-		};
-		for (const decision of artifacts.trace.phases.flatMap(({ decisions }) => decisions))
-			applyReplayDeltas(replay, decision.deltas, artifacts.finalState);
-		expect(
-			[...replay.placements.values()].sort((a, b) => a.date.localeCompare(b.date)),
-		).toEqual(windowFirst.placements);
-		expect(
-			artifacts.trace.phases
-				.filter(({ name }) => name === 'preference:early')
-				.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates)),
-		).toContainEqual(
-			expect.objectContaining({
-				status: 'chosen',
-				placement: expect.objectContaining({ date: '2026-11-03', ruleIds: ['early'] }),
-			}),
-		);
-		expect(updates.length).toBeGreaterThan(0);
-		for (const { update, snapshot } of updates) expect(JSON.stringify(update)).toBe(snapshot);
 		let cancelled = false;
 		let cancelledArtifacts: PlanningArtifacts | undefined;
 		let published: PlanOutcome | undefined;
@@ -605,8 +551,6 @@ describe('supporting placement economy and provenance', () => {
 				progress: (stage: string) => {
 					if (stage === 'optimization:economy') cancelled = true;
 				},
-				traceProgress: (_time: number, update: PlanningTraceUpdate) =>
-					updates.push({ update, snapshot: JSON.stringify(update) }),
 			},
 			(checkpoint, state) => {
 				expect(state?.placements).toEqual(checkpoint.placements);
@@ -637,7 +581,6 @@ describe('supporting placement economy and provenance', () => {
 				expect.objectContaining({ kind: 'rule', ruleId: 'early' }),
 			);
 		}
-		for (const { update, snapshot } of updates) expect(JSON.stringify(update)).toBe(snapshot);
 	});
 
 	it('keeps established maximum credit when a later earned period masks its local contribution', () => {
@@ -708,28 +651,6 @@ describe('supporting placement economy and provenance', () => {
 		});
 	});
 
-	it('records the calendar credit and classification change in the original calendar-rule phase', () => {
-		let artifacts: PlanningArtifacts | undefined;
-		calculatePlanningInternal(
-			{ ...weekend, rules: [gain, economy, requested] },
-			undefined,
-			(value) => (artifacts = value),
-		);
-		const changes = artifacts?.trace?.phases
-			.find(({ name }) => name === 'preference:requested')
-			?.decisions.flatMap(({ deltas }) => deltas);
-		expect(changes).toContainEqual(
-			expect.objectContaining({
-				kind: 'placement-updated',
-				previousPlacement: expect.objectContaining({ supporting: true }),
-				placement: expect.objectContaining({
-					ruleIds: ['gain', 'requested'],
-					supporting: false,
-				}),
-			}),
-		);
-	});
-
 	it('keeps earned support chronological and preserves the captured economy rule in explanations and counterfactuals', async () => {
 		vi.stubGlobal('window', undefined);
 		try {
@@ -792,15 +713,6 @@ describe('supporting placement economy and provenance', () => {
 			expect(supporting.contributions).toContainEqual(
 				expect.objectContaining({ kind: 'supporting' }),
 			);
-			const trace = await calculation.trace;
-			expect(trace?.phases.map(({ name }) => name)).toEqual([
-				'validation',
-				'obligations',
-				'optimization:gain',
-				'optimization:economy',
-				'expiry',
-				'dates',
-			]);
 			const analysis = await calculation.analyzeCounterfactual(outcome.placements[1]);
 			if (analysis.kind !== 'Counterfactual') throw new Error('Expected a counterfactual');
 			expect(analysis.results.find(({ date }) => date === '2024-05-03')).toMatchObject({

src/app/services/leave-planner-work-sequences.spec.ts

@@ -407,7 +407,7 @@ describe('composed work-sequence preferences', () => {
 		},
 	);
 
-	it('captures distinct threshold values in explanations, atomic trace and counterfactual comparisons', async () => {
+	it('captures distinct threshold values in explanations and date comparisons', async () => {
 		vi.stubGlobal('window', undefined);
 		try {
 			const five = structuredClone(deficit);
@@ -435,18 +435,6 @@ describe('composed work-sequence preferences', () => {
 					.filter(({ id }) => id.startsWith('optimization:'))
 					.map(({ value }) => value),
 			).toEqual([2, 4]);
-			const trace = await calculation.trace;
-			const chosen = trace?.phases
-				.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates))
-				.find(
-					(candidate) => candidate.status === 'chosen' && candidate.dates?.length === 3,
-				);
-			expect(
-				chosen?.comparison?.before.objectives
-					.filter(({ id }) => id.startsWith('optimization:'))
-					.map(({ value }) => value),
-			).toEqual([0, 2]);
-			expect(chosen?.comparison?.firstDecisiveObjective).toBe('optimization:deficit');
 			const counterfactual = await calculation.analyzeCounterfactual(outcome.placements[0]);
 			if (counterfactual.kind !== 'Counterfactual')
 				throw new Error('Expected a counterfactual');

src/app/services/leave-planner.worker.spec.ts

@@ -76,15 +76,7 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 						simulatedElapsed = data.elapsed;
 						return;
 					}
-					if (
+					if (holdArtifacts && ['explanation', 'artifacts'].includes(data.type)) {
-						holdArtifacts &&
-						[
-							'explanation',
-							'artifacts-start',
-							'trace-status-index',
-							'artifacts-complete',
-						].includes(data.type)
-					) {
 						heldArtifactMessages.push(() => this.onmessage?.({ data } as MessageEvent));
 						return;
 					}
@@ -152,14 +144,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 			'balance-expiry',
 			'placement-date',
 		]);
-		const trace = await calculation.trace;
-		expect(trace?.phases.map((phase) => phase.name)).toEqual([
-			'validation',
-			'obligations',
-			'optimization:personal-loss',
-			'expiry',
-			'dates',
-		]);
 		const comparison = await calculation.analyzeCounterfactual(outcome.placements[0]);
 		if (comparison.kind !== 'Counterfactual') throw new Error('Expected worker comparison');
 		expect(comparison.baseline.objectives.map((objective) => objective.id)).toEqual([
@@ -170,7 +154,7 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 		]);
 	});
 
-	it('keeps the submitted work-sequence threshold in the real worker, trace and counterfactuals', async () => {
+	it('keeps the submitted work-sequence threshold in the real worker and date comparisons', async () => {
 		const configuration: OptimizationConfiguration = structuredClone(
 			OPTIMIZATION_PRESETS.shortSequenceDeficit,
 		);
@@ -206,15 +190,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 				({ id }) => id === 'optimization:deficit',
 			)?.value,
 		).toBe(4);
-		const trace = await calculation.trace;
-		const chosen = trace?.phases
-			.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates))
-			.find((candidate) => candidate.status === 'chosen' && candidate.dates?.length === 3);
-		expect(chosen?.comparison?.firstDecisiveObjective).toBe('optimization:deficit');
-		expect(
-			chosen?.comparison?.before.objectives.find(({ id }) => id === 'optimization:deficit')
-				?.value,
-		).toBe(2);
 		const counterfactual = await calculation.analyzeCounterfactual(outcome.placements[0]);
 		if (counterfactual.kind !== 'Counterfactual') throw new Error('Expected a counterfactual');
 		expect(
@@ -390,7 +365,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 				for (const deliver of heldArtifactMessages.splice(0)) deliver();
 			}
 			const explanation = await calculation.explanation;
-			const trace = await calculation.trace;
 			await fixture.whenStable();
 			fixture.detectChanges();
 			expect(connectedHolidays()).toBe('1');
@@ -416,11 +390,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 					},
 				],
 			});
-			expect(trace?.initialState).toMatchObject({
-				calculationDate: '2024-05-01',
-				declaredDays: originalDeclarations,
-			});
-			expect(trace?.status).toBe(cancelled ? 'incomplete' : 'ready');
 			const core = await import('./leave-planner.core');
 			const direct = core.calculatePlanningInternal(calculation.snapshot);
 			if (direct.kind !== 'Plan')
@@ -450,24 +419,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 			expect(comparison?.results.find(({ date }) => date === '2024-05-03')?.status).toBe(
 				'eligible',
 			);
-			fixture.componentInstance['showFinalPlan']();
-			if (!trace) throw new Error('Expected the original trace.');
-			const phaseIndex = trace.phases.findIndex(({ decisions }) =>
-				decisions.some(({ deltas }) =>
-					deltas.some(({ placement }) => placement?.balanceId.startsWith('earned:')),
-				),
-			);
-			expect(phaseIndex).toBeGreaterThanOrEqual(0);
-			fixture.componentInstance['selectTracePhase'](phaseIndex);
-			const decisionIndex = trace.phases[phaseIndex].decisions.findIndex(({ deltas }) =>
-				deltas.some(({ placement }) => placement?.balanceId.startsWith('earned:')),
-			);
-			fixture.componentInstance['selectTraceDecision'](decisionIndex);
-			fixture.componentInstance['showTraceMoment']('after');
-			expect(fixture.componentInstance['selectedTraceTransition']()?.after).toMatchObject({
-				calculationDate: '2024-05-01',
-				declaredDays: originalDeclarations,
-			});
 			root.querySelector<HTMLButtonElement>('.statistics-button')!.click();
 			await fixture.whenStable();
 			expect(connectedHolidays()).toBe('1');
@@ -541,9 +492,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 				kind: 'PlanExplanation',
 				declaredDays: submitted.declaredDays,
 			});
-			expect((await calculation.trace)?.initialState.declaredDays).toEqual(
-				submitted.declaredDays,
-			);
 			const original = structuredClone(outcome);
 			const comparison = await calculation.analyzeCounterfactual(plan!.placements[0]);
 			for (const { date } of submitted.declaredDays)
@@ -577,10 +525,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 		expect(outcome.incumbent).toBeUndefined();
 		expect(preparationUpdates).toBeGreaterThanOrEqual(2);
 		expect(stages).not.toContain('obligations');
-		expect(await calculation.trace).toMatchObject({
-			status: 'incomplete',
-			initialState: { declaredDays: [{ date: '2024-01-02', type: 'other' }] },
-		});
 		expect(await calculation.explanationError).toBeUndefined();
 		expect(heartbeats).toBeGreaterThan(0);
 	});
@@ -611,10 +555,9 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 		});
 		if (outcome.kind !== 'PlanningIncomplete') return;
 		expect(outcome.incumbent).toBeUndefined();
-		expect((await calculation.trace)?.status).toBe('incomplete');
 	});
 
-	it('stops an active obligation search and retains a jointly valid incumbent and its history', async () => {
+	it('stops an active obligation search and retains a jointly valid incumbent', async () => {
 		let cancelledAt = 0;
 		afterCheckpoint = () => {
 			afterCheckpoint = undefined;
@@ -663,15 +606,9 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 			);
 			expect(explanation.incomplete?.reason.code).toBe('user-cancelled');
 		}
-		const trace = await calculation.trace;
-		expect(trace?.status).toBe('incomplete');
-		expect(
-			trace?.phases.find((phase) => phase.name === 'obligations')?.decisions.length,
-		).toBeGreaterThan(0);
-		expect(trace?.phases.find((phase) => phase.name === 'dates')?.status).toBe('not-run');
 	});
 
-	it('preserves balances and provenance after a valid checkpoint and drains every produced trace packet', async () => {
+	it('preserves balances and provenance after a valid checkpoint', async () => {
 		const calculation = createPlanningCalculation({
 			horizon: { start: '2024-01-01', end: '2025-01-01' },
 			balances: [{ id: 'cp', type: 'cp', quantity: 3, expiryDate: '2024-12-31' }],
@@ -716,14 +653,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 			expect(explanation.placements.map(({ placement }) => placement)).toEqual(
 				incumbent.placements,
 			);
-		const trace = await calculation.trace;
-		expect(trace?.status).toBe('incomplete');
-		expect(trace?.error?.code).toBe('user-cancelled');
-		expect(
-			trace?.phases.find(
-				(phase) => phase.name === 'optimization:default-non-working-day-gain',
-			)?.status,
-		).toBe('interrupted');
 		const frozenOutcome = structuredClone(outcome);
 		calculation.cancel();
 		expect(await calculation.outcome).toEqual(frozenOutcome);
@@ -750,7 +679,6 @@ parentPort.on('message', (data) => globalThis.self.onmessage({ data }));
 		const calculation = createPlanningCalculation(submitted);
 		expect(await calculation.outcome).toEqual(expected);
 		expect(simulatedElapsed).toBe(20_000);
-		expect((await calculation.trace)?.status).toBe('ready');
 		expect(await calculation.explanationError).toBeUndefined();
 	});
 });

src/app/services/leave-planner.worker.ts

@@ -7,18 +7,13 @@ import type {
 	PlanningExplanation,
 	PlanningOutcome,
 	PlanningReason,
-	PlanningTrace,
-	PlanningTraceUpdate,
 	PlanningSnapshot,
-	PlanningTraceState,
+	PlanningStateSnapshot,
-	TraceCandidateStatus,
 } from './leave-planner.service';
 import {
 	analyzeCounterfactualInternal,
 	calculatePlanningAsyncInternal,
 	explainIncompleteCheckpoint,
-	historicalCounterfactualReasons,
-	type CounterfactualBaselineOptions,
 	type PlanningArtifacts,
 } from './leave-planner.core';
 
@@ -39,271 +34,52 @@ type WorkerRequest =
 			type: 'plan';
 			request: WorkerPlanningRequest;
 	  }
-	| { type: 'trace-ack'; count: number }
 	| { type: 'cancel' }
 	| {
 			type: 'counterfactual';
 			request: PlanningSnapshot;
 			plan: PlanOutcome;
 			placement: LeavePlacement;
-			state?: PlanningTraceState;
+			state?: PlanningStateSnapshot;
-			options?: CounterfactualBaselineOptions;
-	  }
-	| {
-			type: 'historical-eligibility';
-			request: PlanningSnapshot;
-			placement: LeavePlacement;
-			state: PlanningTraceState;
-			options?: CounterfactualBaselineOptions;
 	  }
 	| {
 			type: 'explain-checkpoint';
 			request: PlanningSnapshot;
 			plan: PlanOutcome;
-			state: PlanningTraceState;
+			state: PlanningStateSnapshot;
 			interruption: PlanningReason;
 	  };
 
 type WorkerResponse =
 	| { type: 'heartbeat' }
 	| { type: 'progress'; stage: string }
-	| { type: 'trace-overhead'; totalMs: number }
+	| { type: 'checkpoint'; plan: PlanOutcome; state?: PlanningStateSnapshot }
-	| { type: 'checkpoint'; plan: PlanOutcome; state?: PlanningTraceState }
 	| { type: 'result'; outcome: PlanningOutcome }
 	| { type: 'artifacts'; artifacts: PlanningArtifacts }
 	| {
 			type: 'explanation';
 			explanation?: PlanningExplanation;
 			explanationError?: PlanningReason;
-			finalState?: PlanningTraceState;
+			finalState?: PlanningStateSnapshot;
 	  }
-	| {
-			type: 'artifacts-start';
-			artifacts: Omit<
-				PlanningArtifacts,
-				'trace' | 'explanation' | 'explanationError' | 'finalState'
-			>;
-			trace?: Omit<PlanningTrace, 'phases'>;
-	  }
-	| {
-			type: 'trace-update';
-			totalMs: number;
-			update: PlanningTraceUpdate;
-			acknowledge?: true;
-	  }
-	| {
-			type: 'trace-status-index';
-			statuses: ReadonlyMap<string, TraceCandidateStatus>;
-			nonWorkingDates: readonly string[];
-	  }
-	| { type: 'artifacts-complete'; traceTransferMs: number }
 	| { type: 'counterfactual-result'; analysis: CounterfactualAnalysis }
-	| {
-			type: 'historical-eligibility-result';
-			entries: ReturnType<typeof historicalCounterfactualReasons>;
-	  }
 	| { type: 'error'; code?: string; message: string };
 
 const worker = self as DedicatedWorkerGlobalScope;
-const TRACE_OPERATIONS_PER_MESSAGE = 64;
-const MAX_TRACE_PACKETS_IN_FLIGHT = 16;
-
-interface StagedTraceUpdate {
-	totalMs: number;
-	update?: PlanningTraceUpdate;
-	nextOperation: number;
-}
-
-interface TraceDelivery {
-	updates: StagedTraceUpdate[];
-	nextUpdate: number;
-	inFlight: number;
-	traceTransferMs: number;
-	artifacts?: PlanningArtifacts;
-	calculationComplete: boolean;
-}
-
-let activeTraceDelivery: TraceDelivery | undefined;
 let activeCalculation: { cancelled: boolean } | undefined;
 
-function traceStatusIndex(trace: PlanningTrace): {
-	statuses: Map<string, TraceCandidateStatus>;
-	nonWorkingDates: string[];
-} {
-	const priority: Record<TraceCandidateStatus, number> = {
-		ineligible: 0,
-		'not-examined': 1,
-		pruned: 2,
-		'evaluated-rejected': 3,
-		chosen: 4,
-	};
-	const statuses = new Map<string, TraceCandidateStatus>();
-	const nonWorkingDates = new Set(trace.nonWorkingDates?.map(({ date }) => date) ?? []);
-	for (const phase of trace.phases) {
-		for (const decision of phase.decisions) {
-			for (const candidate of decision.candidates) {
-				const dates = candidate.dates ?? (candidate.date ? [candidate.date] : []);
-				for (const date of dates) {
-					const previous = statuses.get(date);
-					if (!previous || priority[candidate.status] > priority[previous])
-						statuses.set(date, candidate.status);
-				}
-			}
-		}
-	}
-	return { statuses, nonWorkingDates: [...nonWorkingDates] };
-}
-
-function sendArtifacts(artifacts: PlanningArtifacts, deferredTraceTransferMs = 0): void {
-	const trace = artifacts.trace;
-	let traceMaterializationMs = artifacts.timings?.traceMaterializationMs ?? 0;
-	let traceTransferMs = (artifacts.timings?.traceTransferMs ?? 0) + deferredTraceTransferMs;
-	if (trace) {
-		const materializationStarted = performance.now();
-		const statusIndex = traceStatusIndex(trace);
-		traceMaterializationMs += Math.max(0, performance.now() - materializationStarted);
-		const transferStarted = performance.now();
-		worker.postMessage({
-			type: 'trace-status-index',
-			statuses: statusIndex.statuses,
-			nonWorkingDates: statusIndex.nonWorkingDates,
-		} satisfies WorkerResponse);
-		traceTransferMs += Math.max(0, performance.now() - transferStarted);
-	}
-	const rest: Omit<
-		PlanningArtifacts,
-		'trace' | 'explanation' | 'explanationError' | 'finalState'
-	> = artifacts.timings
-		? {
-				timings: {
-					...artifacts.timings,
-					traceMaterializationMs,
-					traceTransferMs,
-				},
-			}
-		: {};
-	const transferStarted = performance.now();
-	worker.postMessage({
-		type: 'artifacts-start',
-		artifacts: rest,
-		trace: trace
-			? {
-					status: trace.status,
-					initialState: trace.initialState,
-					completedStages: trace.completedStages,
-					nonWorkingDates: trace.nonWorkingDates,
-					error: trace.error,
-				}
-			: undefined,
-	} satisfies WorkerResponse);
-	traceTransferMs += Math.max(0, performance.now() - transferStarted);
-	// Capture updates already carried every candidate in bounded operations.
-	// The final packet closes the trace without cloning it a second time.
-	worker.postMessage({ type: 'artifacts-complete', traceTransferMs } satisfies WorkerResponse);
-}
-
-function finishTraceDelivery(delivery: TraceDelivery): void {
-	if (
-		!delivery.calculationComplete ||
-		delivery.nextUpdate < delivery.updates.length ||
-		delivery.inFlight > 0 ||
-		!delivery.artifacts
-	)
-		return;
-	if (activeTraceDelivery === delivery) activeTraceDelivery = undefined;
-	try {
-		sendArtifacts(delivery.artifacts, delivery.traceTransferMs);
-	} catch (error) {
-		worker.postMessage({
-			type: 'error',
-			code: 'trace-error',
-			message: error instanceof Error ? error.message : String(error),
-		} satisfies WorkerResponse);
-	}
-	delivery.updates = [];
-}
-
-function pumpTraceUpdates(delivery: TraceDelivery): void {
-	while (
-		delivery.inFlight < MAX_TRACE_PACKETS_IN_FLIGHT &&
-		delivery.nextUpdate < delivery.updates.length
-	) {
-		const staged = delivery.updates[delivery.nextUpdate];
-		const update = staged.update;
-		if (!update) {
-			delivery.nextUpdate++;
-			continue;
-		}
-		const start = staged.nextOperation;
-		const end = Math.min(start + TRACE_OPERATIONS_PER_MESSAGE, update.operations.length);
-		const firstPacket = start === 0;
-		const packet: WorkerResponse = {
-			type: 'trace-update',
-			totalMs: staged.totalMs,
-			acknowledge: true,
-			update: {
-				initialState: firstPacket ? update.initialState : undefined,
-				nonWorkingDates: firstPacket ? update.nonWorkingDates : undefined,
-				operations: update.operations.slice(start, end),
-			},
-		};
-		const transferStarted = performance.now();
-		try {
-			worker.postMessage(packet satisfies WorkerResponse);
-		} catch (error) {
-			if (activeTraceDelivery === delivery) activeTraceDelivery = undefined;
-			delivery.updates = [];
-			worker.postMessage({
-				type: 'error',
-				code: 'trace-error',
-				message: error instanceof Error ? error.message : String(error),
-			} satisfies WorkerResponse);
-			return;
-		}
-		delivery.traceTransferMs += Math.max(0, performance.now() - transferStarted);
-		delivery.inFlight++;
-		staged.nextOperation = end;
-		if (update.operations.length === 0 || end >= update.operations.length) {
-			// Drop the full drain array as soon as its last bounded packet is posted.
-			staged.update = undefined;
-			delivery.nextUpdate++;
-		}
-	}
-	if (delivery.nextUpdate === delivery.updates.length) {
-		// All queued operation arrays are released; only in-flight structured clones remain.
-		delivery.updates = [];
-		delivery.nextUpdate = 0;
-	}
-	finishTraceDelivery(delivery);
-}
-
 worker.onmessage = async (event: MessageEvent<WorkerRequest>) => {
 	try {
 		if (event.data?.type === 'cancel') {
 			if (activeCalculation) activeCalculation.cancelled = true;
 			return;
 		}
-		if (event.data?.type === 'trace-ack') {
-			const delivery = activeTraceDelivery;
-			if (!delivery || !Number.isInteger(event.data.count) || event.data.count <= 0) return;
-			delivery.inFlight = Math.max(0, delivery.inFlight - event.data.count);
-			pumpTraceUpdates(delivery);
-			return;
-		}
 		if (event.data?.type === 'plan') {
 			const calculation = { cancelled: false };
 			activeCalculation = calculation;
 			let artifacts: PlanningArtifacts = {};
 			let outcomePosted = false;
 			let outcome: PlanningOutcome;
-			const traceDelivery: TraceDelivery = {
-				updates: [],
-				nextUpdate: 0,
-				inFlight: 0,
-				traceTransferMs: 0,
-				calculationComplete: false,
-			};
-			activeTraceDelivery = traceDelivery;
 			// The cooperative driver yields during preparation and search, even within one phase.
 			const heartbeat = () =>
 				worker.postMessage({ type: 'heartbeat' } satisfies WorkerResponse);
@@ -318,13 +94,6 @@ worker.onmessage = async (event: MessageEvent<WorkerRequest>) => {
 								type: 'progress',
 								stage,
 							} satisfies WorkerResponse),
-						traceProgress: (totalMs: number, update: PlanningTraceUpdate) => {
-							worker.postMessage({
-								type: 'trace-overhead',
-								totalMs,
-							} satisfies WorkerResponse);
-							traceDelivery.updates.push({ totalMs, update, nextOperation: 0 });
-						},
 					},
 					(plan, state) =>
 						worker.postMessage({
@@ -350,8 +119,6 @@ worker.onmessage = async (event: MessageEvent<WorkerRequest>) => {
 					() => calculation.cancelled,
 				);
 			} catch (error) {
-				if (activeTraceDelivery === traceDelivery) activeTraceDelivery = undefined;
-				traceDelivery.updates = [];
 				worker.postMessage({
 					type: 'error',
 					code: 'planner-error',
@@ -364,9 +131,7 @@ worker.onmessage = async (event: MessageEvent<WorkerRequest>) => {
 			}
 			if (!outcomePosted)
 				worker.postMessage({ type: 'result', outcome } satisfies WorkerResponse);
-			traceDelivery.artifacts = artifacts;
+			worker.postMessage({ type: 'artifacts', artifacts } satisfies WorkerResponse);
-			traceDelivery.calculationComplete = true;
-			pumpTraceUpdates(traceDelivery);
 			return;
 		}
 		if (event.data?.type === 'explain-checkpoint') {
@@ -379,44 +144,14 @@ worker.onmessage = async (event: MessageEvent<WorkerRequest>) => {
 			worker.postMessage({ type: 'explanation', ...result } satisfies WorkerResponse);
 			return;
 		}
-		if (event.data?.type === 'historical-eligibility') {
-			worker.postMessage({
-				type: 'historical-eligibility-result',
-				entries: historicalCounterfactualReasons(
-					event.data.request,
-					event.data.state,
-					event.data.placement,
-					event.data.options,
-				),
-			} satisfies WorkerResponse);
-			return;
-		}
 		if (event.data?.type !== 'counterfactual') return;
 		try {
-			let analysis = analyzeCounterfactualInternal(
+			const analysis = analyzeCounterfactualInternal(
 				event.data.request,
 				event.data.plan,
 				event.data.placement,
 				event.data.state,
-				event.data.options,
 			);
-			if (event.data.options && event.data.state) {
-				const historicalReasons = new Map(
-					historicalCounterfactualReasons(
-						event.data.request,
-						event.data.state,
-						event.data.placement,
-						event.data.options,
-					).map(({ date, reason }) => [date, reason]),
-				);
-				analysis = {
-					...analysis,
-					results: analysis.results.map((result) => {
-						const historicalReason = historicalReasons.get(result.date);
-						return historicalReason ? { ...result, historicalReason } : result;
-					}),
-				};
-			}
 			worker.postMessage({
 				type: 'counterfactual-result',
 				analysis,

src/app/services/optimization-integration.spec.ts

@@ -42,7 +42,7 @@ describe('integrated optimization and earned leave', () => {
 		},
 	);
 
-	it('runs the complete configuration once after the sole obligation state and records exact reused evaluations', () => {
+	it('uses the complete configuration after the sole obligation state', () => {
 		let artifacts: PlanningArtifacts = {};
 		const outcome = calculatePlanningInternal(
 			composedRequest,
@@ -54,27 +54,6 @@ describe('integrated optimization and earned leave', () => {
 			placements: [{ date: '2024-05-06' }, { date: '2024-05-07' }, { date: '2024-05-10' }],
 			metrics: { unplacedAtRisk: 0, holidayWeekValue: 5, nonWorkingDayGain: 6 },
 		});
-		const trace = artifacts.trace;
-		expect(trace?.status).toBe('ready');
-		expect(
-			trace?.phases
-				.find(({ name }) => name === 'obligations')
-				?.decisions.flatMap(({ candidates }) => candidates)
-				.some(({ comparison }) => comparison),
-		).toBe(false);
-		expect(
-			trace?.phases
-				.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates))
-				.some(({ reason }) => reason?.code === 'unchanged-rule-state'),
-		).toBe(true);
-		expect(
-			trace?.phases
-				.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates))
-				.some(
-					({ status, reason }) =>
-						status === 'not-examined' && reason?.code === 'unchanged-generic-state',
-				),
-		).toBe(true);
 		if (artifacts.explanation?.kind !== 'PlanExplanation')
 			throw new Error('Expected an explanation.');
 		expect(
@@ -93,9 +72,7 @@ describe('integrated optimization and earned leave', () => {
 	});
 
 	it('preserves the first equivalent funder while evaluating typed window alternatives', () => {
-		let artifacts: PlanningArtifacts = {};
+		const outcome = calculatePlanningInternal({
-		const outcome = calculatePlanningInternal(
-			{
 			...composedRequest,
 			balances: ['first-cp', 'second-cp', 'rtt'].map((id) => ({
 				id,
@@ -116,10 +93,7 @@ describe('integrated optimization and earned leave', () => {
 				},
 				...presets.slice(1),
 			],
-			},
+		});
-			undefined,
-			(value) => (artifacts = value),
-		);
 		expect(outcome).toMatchObject({
 			kind: 'Plan',
 			placements: [
@@ -130,35 +104,12 @@ describe('integrated optimization and earned leave', () => {
 			preferences: [{ ruleId: 'typed-window', satisfied: 1 }],
 			metrics: { unplacedAtRisk: 0, holidayWeekValue: 5, nonWorkingDayGain: 6 },
 		});
-		const candidates = artifacts.trace?.phases
-			.find(({ name }) => name === `optimization:${presets[0].id}`)
-			?.decisions.flatMap(({ candidates }) => candidates);
-		const skipped = candidates?.filter(
-			({ reason }) => reason?.code === 'equivalent-date-funding',
-		);
-		expect(skipped?.length).toBeGreaterThan(0);
-		expect(
-			skipped?.every(({ status, comparison }) => status === 'not-examined' && !comparison),
-		).toBe(true);
-		expect(
-			skipped?.some(
-				({ date, placement }) => date === '2024-05-07' && placement?.balanceId === 'rtt',
-			),
-		).toBe(false);
-		expect(
-			candidates?.some(
-				({ date, placement, comparison }) =>
-					date === '2024-05-07' && placement?.balanceId === 'rtt' && comparison,
-			),
-		).toBe(true);
 	});
 
 	it.each(['maximum', 'unsafe-total'] as const)(
 		'keeps distinct funding evaluations when equivalence cannot be proved (%s)',
 		(control) => {
-			let artifacts: PlanningArtifacts = {};
+			const outcome = calculatePlanningInternal({
-			const outcome = calculatePlanningInternal(
-				{
 				calculationDate: '2024-01-01',
 				horizon: { start: '2024-01-02', end: '2024-01-03' },
 				balances: [
@@ -190,40 +141,19 @@ describe('integrated optimization and earned leave', () => {
 							]
 						: []),
 				],
-				},
+			});
-				undefined,
-				(value) => (artifacts = value),
-			);
 			expect(outcome).toMatchObject({
 				kind: 'Plan',
 				placements: [{ balanceId: control === 'maximum' ? 'second' : 'first' }],
 			});
-			const candidates = artifacts.trace?.phases
-				.find(({ name }) => name === `optimization:${presets[0].id}`)
-				?.decisions.flatMap(({ candidates }) => candidates);
-			expect(
-				candidates?.some(({ reason }) => reason?.code === 'equivalent-date-funding'),
-			).toBe(false);
-			for (const balanceId of ['first', 'second'])
-				expect(
-					candidates?.some(
-						({ placement, comparison }) =>
-							placement?.balanceId === balanceId && comparison,
-					),
-				).toBe(true);
 		},
 	);
 
 	it('finishes a renamed first quantity rule at zero and still evaluates later priorities and final ties', () => {
 		const loss = { ...presets[0], id: 'personal-quantity', name: 'Personal quantity' };
 		const run = (rules: PlanningRequest['rules']) => {
-			let artifacts: PlanningArtifacts = {};
+			const outcome = calculatePlanningInternal({ ...composedRequest, rules });
-			const outcome = calculatePlanningInternal(
+			return { outcome };
-				{ ...composedRequest, rules },
-				undefined,
-				(value) => (artifacts = value),
-			);
-			return { outcome, trace: artifacts.trace };
 		};
 		const window = {
 			id: 'already-satisfied',
@@ -239,40 +169,8 @@ describe('integrated optimization and earned leave', () => {
 			placements: [{ date: '2024-05-06' }, { date: '2024-05-07' }, { date: '2024-05-10' }],
 			metrics: { unplacedAtRisk: 0, holidayWeekValue: 5, nonWorkingDayGain: 6 },
 		});
-		const stopped = first.trace?.phases
-			.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates))
-			.filter(({ reason }) => reason?.code === 'quantity-prefix-lower-bound');
-		expect(stopped?.length).toBeGreaterThan(0);
-		expect(
-			stopped?.every(
-				({ status, reason }) =>
-					status === 'not-examined' && reason?.ruleIds?.includes(loss.id),
-			),
-		).toBe(true);
-		expect(
-			first.trace?.phases
-				.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates))
-				.some(
-					({ status, reason }) =>
-						status === 'not-examined' &&
-						reason?.code === 'satisfied-window-prefix-bound' &&
-						reason.ruleIds?.includes(window.id),
-				),
-		).toBe(true);
-		const expiry = first.trace?.phases.find(({ name }) => name === 'expiry');
-		expect(expiry?.completed).toBe(true);
-		expect(
-			expiry?.decisions.some(({ candidates }) =>
-				candidates.some(({ comparison }) => comparison),
-			),
-		).toBe(true);
 		const reordered = run([presets[1], loss, ...presets.slice(2)]);
 		expect(reordered.outcome.kind).toBe('Plan');
-		expect(
-			reordered.trace?.phases
-				.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates))
-				.some(({ reason }) => reason?.code === 'quantity-prefix-lower-bound'),
-		).toBe(false);
 	});
 
 	it.each(['sum', 'count', 'maximum'] as const)(
@@ -283,12 +181,10 @@ describe('integrated optimization and earned leave', () => {
 				id: 'personal-holiday',
 				configuration: { ...OPTIMIZATION_PRESETS.holidayWeekValue, aggregation },
 			};
-			let artifacts: PlanningArtifacts = {};
+			const outcome = calculatePlanningInternal({
-			const outcome = calculatePlanningInternal(
+				...composedRequest,
-				{ ...composedRequest, rules: [presets[0], holiday, ...presets.slice(2)] },
+				rules: [presets[0], holiday, ...presets.slice(2)],
-				undefined,
+			});
-				(value) => (artifacts = value),
-			);
 			expect(outcome).toMatchObject({
 				kind: 'Plan',
 				placements: [
@@ -298,30 +194,11 @@ describe('integrated optimization and earned leave', () => {
 				],
 				metrics: { unplacedAtRisk: 0, holidayWeekValue: 5, nonWorkingDayGain: 6 },
 			});
-			expect(
-				artifacts.trace?.phases
-					.flatMap(({ decisions }) => decisions.flatMap(({ candidates }) => candidates))
-					.some(
-						({ status, reason }) =>
-							status === 'not-examined' &&
-							reason?.code === 'satisfied-holiday-prefix-bound' &&
-							reason.ruleIds?.includes(holiday.id),
-					),
-			).toBe(true);
-			const final = artifacts.trace?.phases.find(({ name }) => name === 'expiry');
-			expect(final?.completed).toBe(true);
-			expect(
-				final?.decisions.some(({ candidates }) =>
-					candidates.some(({ comparison }) => comparison),
-				),
-			).toBe(true);
 		},
 	);
 
 	it('commits a strict holiday bundle before deferring old generic alternatives and preserves higher rules', () => {
-		let artifacts: PlanningArtifacts = {};
+		const outcome = calculatePlanningInternal({
-		const outcome = calculatePlanningInternal(
-			{
 			calculationDate: '2026-11-01',
 			horizon: { start: '2026-11-02', end: '2026-11-14' },
 			balances: [{ id: 'cp', type: 'cp', quantity: 3, expiryDate: '2026-11-30' }],
@@ -347,36 +224,13 @@ describe('integrated optimization and earned leave', () => {
 				},
 				...presets.slice(1),
 			],
-			},
+		});
-			undefined,
-			(value) => (artifacts = value),
-		);
 		expect(outcome).toMatchObject({
 			kind: 'Plan',
 			placements: [{ date: '2026-11-02' }, { date: '2026-11-12' }, { date: '2026-11-13' }],
 			preferences: [{ ruleId: 'earlier-window', satisfied: 1 }],
 			metrics: { unplacedAtRisk: 0, holidayWeekValue: 3 },
 		});
-		const holiday = artifacts.trace?.phases.find(
-			({ name }) => name === `optimization:${presets[1].id}`,
-		);
-		const decisions = holiday?.decisions.flatMap(({ candidates }) => candidates);
-		expect(
-			decisions?.some(
-				({ status, reason }) =>
-					status === 'not-examined' && reason?.code === 'strict-prefix-bundle-progress',
-			),
-		).toBe(true);
-		expect(decisions?.some(({ status, comparison }) => status === 'chosen' && comparison)).toBe(
-			true,
-		);
-		const final = artifacts.trace?.phases.find(({ name }) => name === 'expiry');
-		expect(final?.completed).toBe(true);
-		expect(
-			final?.decisions.some(({ candidates }) =>
-				candidates.some(({ comparison }) => comparison),
-			),
-		).toBe(true);
 	});
 
 	it.each([false, true])(

src/app/services/optimization-rule.spec.ts

@@ -254,17 +254,6 @@ describe('explicit active planning objectives', () => {
 		const outcome = await calculation.outcome;
 		if (outcome.kind !== 'Plan') throw new Error('Expected a valid plan');
 		expect(outcome.metrics.unplacedAtRisk).toBe(0);
-		const trace = await calculation.trace;
-		expect(
-			trace?.phases
-				.flatMap(({ decisions }) => decisions)
-				.flatMap(({ candidates }) => candidates)
-				.some(
-					({ sourceDate, dates }) =>
-						sourceDate === '2024-01-02' &&
-						dates?.join(',') === '2024-01-02,2024-01-03,2024-01-04',
-				),
-		).toBe(true);
 	});
 
 	it('satisfies a lower IF_THEN pattern by reassigning its complete typed bundle', async () => {
@@ -376,17 +365,6 @@ describe('explicit active planning objectives', () => {
 			expect(
 				outcome.placements.filter(({ ruleIds }) => ruleIds.includes(rule.id)),
 			).toHaveLength(2);
-		const trace = await calculation.trace;
-		expect(
-			trace?.phases
-				.flatMap(({ decisions }) => decisions)
-				.flatMap(({ candidates }) => candidates)
-				.some(
-					({ status, reason }) =>
-						status === 'not-examined' &&
-						reason?.code === 'window-obligation-preview-sampling',
-				),
-		).toBe(true);
 		const reversed = await createPlanningCalculation({
 			...request,
 			rules: [...obligations, personal, loss],
@@ -492,15 +470,6 @@ describe('explicit active planning objectives', () => {
 		expect(explanation.placements[0].objectiveVector.objectives[1].label).toBe(
 			'Prevent losses',
 		);
-		const trace = await calculation.trace;
-		expect(trace?.phases.map((phase) => phase.name)).toEqual([
-			'validation',
-			'obligations',
-			'optimization:loss',
-			'preference:personal',
-			'expiry',
-			'dates',
-		]);
 		const comparison = await calculation.analyzeCounterfactual(outcome.placements[0]);
 		if (comparison.kind !== 'Counterfactual') throw new Error('Expected comparison');
 		expect(comparison.baseline.objectives.map((objective) => objective.id)).toEqual(ids);

src/app/services/rule-migration.spec.ts

@@ -241,12 +241,6 @@ describe('saved rule migration', () => {
 					},
 				],
 			});
-			expect((await calculation.trace)?.phases.map(({ name }) => name)).toEqual([
-				'validation',
-				'obligations',
-				'expiry',
-				'dates',
-			]);
 			expect(await calculation.explanation).toMatchObject({
 				kind: 'PlanExplanation',
 				placements: [],
@@ -277,12 +271,5 @@ describe('saved rule migration', () => {
 			metrics: { unplacedAtRisk: 0 },
 			placements: [{ balanceId: 'cp' }],
 		});
-		expect((await calculation.trace)?.phases.map(({ name }) => name)).toEqual([
-			'validation',
-			'obligations',
-			...request.rules.map(({ id }) => `optimization:${id}`),
-			'expiry',
-			'dates',
-		]);
 	});
 });

src/app/services/translation-service.ts

@@ -39,14 +39,10 @@ export interface AppTranslations {
 		durationEstimate: string;
 		durationUnits: { seconds: string; minutes: string };
 		remainingDaysWarning: string;
-		remainingWhy: string;
 		remainingValidity: string;
 		remainingHorizon: string;
 		remainingEarnedFrom: string;
-		remainingHistoryHelp: string;
-		remainingNoEvaluations: string;
 		remainingSuggestions: Record<string, string>;
-		remainingCandidateReasons: Record<string, string>;
 		deleteEntry: string;
 		chooseDate: string;
 		availableDate: string;
@@ -177,7 +173,6 @@ export interface AppTranslations {
 		includedEntitlement: string;
 		comparison: {
 			title: string;
-			candidate: string;
 			preview: string;
 			nearby: string;
 			noAlternatives: string;
@@ -188,7 +183,6 @@ export interface AppTranslations {
 			available: string;
 			unavailable: string;
 			backToPlan: string;
-			backToTrace: string;
 		};
 		details: {
 			intro: string;
@@ -197,10 +191,6 @@ export interface AppTranslations {
 			expires: string;
 			criteria: string;
 			criteriaHelp: string;
-			traceImpactTitle: string;
-			traceImpactHelp: string;
-			traceStageTitle: string;
-			traceStageHelp: string;
 			firstDifference: string;
 			higher: string;
 			lower: string;
@@ -233,9 +223,6 @@ export interface AppTranslations {
 			alternative: string;
 			sameDate: string;
 			moveHelp: string;
-			traceHelp: string;
-			beforeDecision: string;
-			withCandidate: string;
 			comparisonUnavailable: string;
 			objectives: Record<string, { label: string; help: string }>;
 			preferenceHelp: Record<string, string | undefined>;
@@ -245,11 +232,9 @@ export interface AppTranslations {
 		title: string;
 		calendarHelp: string;
 		explanationHelp: string;
-		traceHelp: string;
 		technicalDetails: string;
 		compareDates: string;
 		stopComparing: string;
-		replayNotice: string;
 		daysPlaced: string;
 		daysGained: string;
 		longestWorkSequence: string;
@@ -267,7 +252,6 @@ export interface AppTranslations {
 		placementNavigation: string;
 		placement: string;
 		placements: string;
-		decision: string;
 		of: string;
 		first: string;
 		previous: string;
@@ -280,13 +264,8 @@ export interface AppTranslations {
 		counterfactualReady: string;
 		counterfactualError: string;
 		retryCounterfactual: string;
-		historicalEligibilityLoading: string;
-		historicalEligibilityReady: string;
-		historicalEligibilityError: string;
-		retryHistoricalEligibility: string;
 		eligible: string;
 		ineligible: string;
-		historical: string;
 		reason: string;
 		explanationError: string;
 		conflictDetails: string;
@@ -300,53 +279,6 @@ export interface AppTranslations {
 		currentPlacement: string;
 		explainedPeriod: string;
 		outsideHorizon: string;
-		traceTitle: string;
-		traceLoading: string;
-		traceReady: string;
-		traceUnavailable: string;
-		phases: string;
-		firstPhase: string;
-		previousPhase: string;
-		nextPhase: string;
-		lastPhase: string;
-		decisions: string;
-		firstDecision: string;
-		previousDecision: string;
-		nextDecision: string;
-		lastDecision: string;
-		replay: string;
-		before: string;
-		after: string;
-		finalPlan: string;
-		dates: string;
-		candidates: string;
-		previousCandidates: string;
-		nextCandidates: string;
-		page: string;
-		compareAlternatives: string;
-		deltas: string;
-		activations: string;
-		noDecisions: string;
-		traceStatuses: {
-			chosen: string;
-			'evaluated-rejected': string;
-			pruned: string;
-			'not-examined': string;
-			ineligible: string;
-		};
-		tracePhaseStatuses: {
-			completed: string;
-			interrupted: string;
-			'not-run': string;
-		};
-		traceChanges: {
-			added: string;
-			'moved-from': string;
-			'moved-to': string;
-			removed: string;
-			shared: string;
-			unchanged: string;
-		};
 	};
 	benchmark: {
 		title: string;

src/app/services/user-input-service.ts

@@ -6,12 +6,7 @@ import {
 	isWorkingPlanningDate,
 	parseDeclaredDays,
 } from './declared-non-working-days';
-import type {
+import type { LeaveType, PlanningOutcome, PlanningSnapshot } from './leave-planner.service';
-	LeaveType,
-	PlanningOutcome,
-	PlanningSnapshot,
-	PlanningTrace,
-} from './leave-planner.service';
 
 @Injectable({
 	providedIn: 'root',
@@ -169,8 +164,6 @@ export class UserInputService {
 	readonly remainingVacationDaysSignal = signal<VacDay[]>([]);
 	readonly planningOutcomeSignal = signal<PlanningOutcome | null>(null);
 	readonly planningSnapshotSignal = signal<PlanningSnapshot | null>(null);
-	readonly planningTraceSignal = signal<PlanningTrace | null>(null);
-	readonly traceResolvedSignal = signal(false);
 	readonly displayedPlanSignal = computed(() => {
 		const outcome = this.planningOutcomeSignal();
 		return outcome?.kind === 'Plan'

src/i18n/de.json

@@ -34,25 +34,15 @@
 		"daySuffix": "Tag",
 		"daysSuffix": "Tage",
 		"expires": "abl.",
-		"remainingWhy": "Warum?",
 		"remainingValidity": "Nutzbar vom {available} bis zum {expiry}.",
 		"remainingHorizon": "Berechneter Plan vom {start} bis zum {end}.",
 		"remainingEarnedFrom": "Durch die Regel „{rule}“ erworbener Urlaub.",
-		"remainingHistoryHelp": "Diese Daten wurden während der Berechnung tatsächlich geprüft. Die Werte vergleichen jeden Versuch mit seinem Ausgangszustand; der endgültige Plan kann abweichen.",
-		"remainingNoEvaluations": "Für dieses Urlaubskonto wurde kein zuordenbarer Versuch aufgezeichnet. Die Ablaufkategorie allein erklärt nicht, warum es ungenutzt bleibt.",
 		"remainingSuggestions": {
 			"available-after-horizon": "Sie können den Planungszeitraum über das Verfügbarkeitsdatum hinaus verlängern und neu berechnen.",
 			"no-working-date": "Prüfen Sie den Planungszeitraum und die Gültigkeitsdaten dieses Urlaubskontos.",
 			"all-dates-occupied": "Sie können den Zeitraum bei entsprechender Gültigkeit verlängern oder Ihre bereits gebuchten Tage und Regeln anpassen und neu berechnen.",
 			"preserved": "Keine Aktion nötig. Um die Nutzung anzufordern, fügen Sie eine Regel innerhalb der Gültigkeit hinzu und berechnen Sie neu.",
 			"calculation-incomplete": "Starten Sie die Berechnung erneut, wenn Sie die Planung abschließen möchten."
-		},
-		"remainingCandidateReasons": {
-			"quality-no-improvement": "Diese Möglichkeit wurde in dieser Berechnungsphase nicht ausgewählt.",
-			"quality-protected-objective": "Diese Möglichkeit würde eine zu erhaltende Priorität verschlechtern.",
-			"quality-outperformed": "Die Berechnung fand später eine besser bewertete Möglichkeit.",
-			"earned-entitlement-order": "Diese Möglichkeit hält die Verfügbarkeitsdaten des erworbenen Urlaubs nicht ein.",
-			"unknown": "Der genaue Grund für diesen Versuch ist nicht verfügbar."
 		}
 	},
 	"dayTypes": {
@@ -218,7 +208,6 @@
 		"placementNavigation": "Navigation der Platzierungserklärungen",
 		"placement": "Urlaubstag",
 		"placements": "Platzierungen",
-		"decision": "Entscheidung",
 		"of": "von",
 		"first": "Erste Platzierung",
 		"previous": "Vorherige Platzierung",
@@ -231,13 +220,8 @@
 		"counterfactualReady": "Alternative Termine sind bereit.",
 		"counterfactualError": "Alternative Termine konnten nicht berechnet werden.",
 		"retryCounterfactual": "Datumsanalyse erneut versuchen",
-		"historicalEligibilityLoading": "Prüfe, an welchen Tagen dieses Urlaubsguthaben verfügbar war …",
-		"historicalEligibilityReady": "Die historische Datumseignung ist bereit.",
-		"historicalEligibilityError": "Die historische Datumseignung konnte nicht geprüft werden.",
-		"retryHistoricalEligibility": "Historische Datumseignung erneut prüfen",
 		"eligible": "Geeignet",
 		"ineligible": "Nicht geeignet",
-		"historical": "Status der ursprünglichen Suche",
 		"reason": "Grund",
 		"explanationError": "Die Erklärung konnte nicht erstellt werden.",
 		"conflictDetails": "Warum kein Plan die Verpflichtungen erfüllt",
@@ -251,60 +235,11 @@
 		"currentPlacement": "Aktuell erklärte Platzierung",
 		"explainedPeriod": "Erklärter Freizeitzeitraum",
 		"outsideHorizon": "Kontextdatum außerhalb des Planungshorizonts",
-		"traceTitle": "Erweitert: ursprüngliche Entscheidungsspur",
-		"traceLoading": "Der Plan ist fertig; seine Entscheidungsspur wird noch geladen…",
-		"traceReady": "Der Plan ist fertig und seine Entscheidungsspur wurde geladen.",
-		"traceUnavailable": "Für dieses Ergebnis ist keine Entscheidungsspur verfügbar.",
-		"phases": "Spurphasen",
-		"firstPhase": "Erste Phase",
-		"previousPhase": "Vorherige Phase",
-		"nextPhase": "Nächste Phase",
-		"lastPhase": "Letzte Phase",
-		"decisions": "Atomare Entscheidungen",
-		"firstDecision": "Erste Entscheidung",
-		"previousDecision": "Vorherige Entscheidung",
-		"nextDecision": "Nächste Entscheidung",
-		"lastDecision": "Letzte Entscheidung",
-		"replay": "Entscheidungszustand",
-		"before": "Vorher",
-		"after": "Nachher",
-		"finalPlan": "Endgültiger Plan",
-		"dates": "Daten",
-		"candidates": "Kandidaten",
-		"previousCandidates": "Vorherige Kandidatenseite",
-		"nextCandidates": "Nächste Kandidatenseite",
-		"page": "Seite",
-		"compareAlternatives": "Diesen Kandidaten im gesamten Horizont vergleichen",
-		"deltas": "Zustandsänderungen",
-		"activations": "erworbene Aktivierungen",
-		"noDecisions": "Diese Phase enthält keine atomare Entscheidung.",
-		"traceStatuses": {
-			"chosen": "Ausgewählt",
-			"evaluated-rejected": "Bewertet und abgelehnt",
-			"pruned": "Verworfen",
-			"not-examined": "Nicht untersucht",
-			"ineligible": "Nicht geeignet"
-		},
-		"tracePhaseStatuses": {
-			"completed": "Abgeschlossen",
-			"interrupted": "Unterbrochen",
-			"not-run": "Nicht ausgeführt"
-		},
-		"traceChanges": {
-			"added": "Durch diese Entscheidung hinzugefügt",
-			"moved-from": "Von diesem Datum verschoben",
-			"moved-to": "Auf dieses Datum verschoben",
-			"removed": "Durch diese Entscheidung entfernt",
-			"shared": "Durch diese Entscheidung geteilt",
-			"unchanged": "Durch diese Entscheidung unverändert"
-		},
 		"calendarHelp": "Wählen Sie einen Urlaubstag, um seinen Beitrag zum Plan zu sehen.",
 		"explanationHelp": "Sehen Sie Ihre Auszeit und den Beitrag jedes Tages.",
-		"traceHelp": "Erkunden Sie die Berechnung, Entscheidung für Entscheidung.",
 		"technicalDetails": "Berechnungsdetails",
 		"compareDates": "Andere Termine vergleichen",
 		"stopComparing": "Datumsvergleich schließen",
-		"replayNotice": "Sie sehen einen Berechnungsschritt.",
 		"explanation": {
 			"breakTitle": "Ihre Auszeit",
 			"leaveDays": "eingesetzte Urlaubstage",
@@ -328,9 +263,6 @@
 			"alternative": "Mit diesem Datum",
 			"sameDate": "Dies ist das geplante Datum. Wählen Sie oben ein anderes Datum, um den Unterschied zu sehen.",
 			"moveHelp": "Verschieben Sie probeweise diesen Tag. Alle anderen Urlaubstermine bleiben gleich.",
-			"traceHelp": "Vergleichen Sie diesen Kandidaten mit dem Zustand vor seiner ursprünglichen Entscheidung.",
-			"beforeDecision": "Vor dieser Entscheidung",
-			"withCandidate": "Mit diesem Kandidaten",
 			"comparisonUnavailable": "Der Vergleich für das ursprüngliche Datum ist nicht verfügbar. Daher lässt sich die Änderung nicht anzeigen.",
 			"objectives": {
 				"obligation-validity": {
@@ -407,10 +339,6 @@
 			"expires": "Verfällt am",
 			"criteria": "Die Prioritäten des Planers",
 			"criteriaHelp": "Von oben nach unten lesen: Der erste Unterschied hat Vorrang. Wählen Sie ein Kriterium, um seine Berechnung zu sehen.",
-			"traceImpactTitle": "Auswirkung dieses Zweigs auf den Gesamtplan",
-			"traceImpactHelp": "Diese Werte vergleichen den vollständigen Zustand vor und nach diesem Zweig. Sie zeigen seine Auswirkungen, aber nicht, warum der Planer ihn gewählt hat.",
-			"traceStageTitle": "Tatsächlicher Vergleich in dieser Planungsstufe",
-			"traceStageHelp": "Diese Rohwerte wurden bei dieser Entscheidung verglichen; der erste Unterschied erklärt den Status des Zweigs. Die Tabelle zum Gesamtplan unten zeigt die Auswirkung dieser Wahl.",
 			"firstDifference": "Erster Unterschied",
 			"higher": "Höher ist besser",
 			"lower": "Niedriger ist besser",
@@ -431,7 +359,6 @@
 		},
 		"comparison": {
 			"title": "Daten vergleichen",
-			"candidate": "Datum des Kandidaten",
 			"preview": "Nur eine Vorschau. Ihr Plan bleibt unverändert.",
 			"nearby": "Verfügbare Termine in der Nähe",
 			"noAlternatives": "Dieser Urlaubstag kann auf kein anderes Datum gelegt werden. Sie können trotzdem ein Datum prüfen, um den Grund zu sehen.",
@@ -441,8 +368,7 @@
 			"changes": "Was sich ändern würde",
 			"available": "Verfügbares Datum",
 			"unavailable": "Dieses Datum ist nicht möglich",
-			"backToPlan": "Zurück zu meinem Plan",
+			"backToPlan": "Zurück zu meinem Plan"
-			"backToTrace": "Zurück zur Berechnung"
 		}
 	},
 	"benchmark": {

src/i18n/en.json

@@ -34,25 +34,15 @@
 		"daySuffix": "day",
 		"daysSuffix": "days",
 		"expires": "exp.",
-		"remainingWhy": "See why",
 		"remainingValidity": "Usable from {available} through {expiry}.",
 		"remainingHorizon": "Calculated plan from {start} through {end}.",
 		"remainingEarnedFrom": "Leave earned through the rule “{rule}”.",
-		"remainingHistoryHelp": "These dates were actually examined during the calculation. The values compare each attempt with its starting state; the final plan may differ.",
-		"remainingNoEvaluations": "No attempt attributable to this balance was recorded. Its expiry category alone does not explain why it remains unused.",
 		"remainingSuggestions": {
 			"available-after-horizon": "You can extend the planning period beyond its availability date, then recalculate.",
 			"no-working-date": "Check the planning period and this balance’s validity dates.",
 			"all-dates-occupied": "You can extend the period if validity allows, or adjust your already booked days and rules, then recalculate.",
 			"preserved": "No action needed. To request its use, add a rule within its validity period, then recalculate.",
 			"calculation-incomplete": "Run the calculation again if you want it to finish planning."
-		},
-		"remainingCandidateReasons": {
-			"quality-no-improvement": "This option was not retained at this stage of the calculation.",
-			"quality-protected-objective": "This option would worsen a priority that must be preserved.",
-			"quality-outperformed": "The calculation later found a better-ranked option.",
-			"earned-entitlement-order": "This option does not respect the availability dates of earned leave.",
-			"unknown": "The precise reason for this attempt is unavailable."
 		}
 	},
 	"dayTypes": {
@@ -218,7 +208,6 @@
 		"placementNavigation": "Placement explanation navigation",
 		"placement": "Leave day",
 		"placements": "placements",
-		"decision": "Decision",
 		"of": "of",
 		"first": "First placement",
 		"previous": "Previous placement",
@@ -231,13 +220,8 @@
 		"counterfactualReady": "Date alternatives are ready.",
 		"counterfactualError": "Date alternatives could not be calculated.",
 		"retryCounterfactual": "Retry date analysis",
-		"historicalEligibilityLoading": "Checking which dates this leave could use…",
-		"historicalEligibilityReady": "Original date eligibility is ready.",
-		"historicalEligibilityError": "Original date eligibility could not be checked.",
-		"retryHistoricalEligibility": "Retry date eligibility check",
 		"eligible": "Eligible",
 		"ineligible": "Ineligible",
-		"historical": "Original search status",
 		"reason": "Reason",
 		"explanationError": "The explanation could not be produced.",
 		"conflictDetails": "Why no plan can satisfy the obligations",
@@ -251,60 +235,11 @@
 		"currentPlacement": "Current explained placement",
 		"explainedPeriod": "Explained time-off period",
 		"outsideHorizon": "Context date outside the planning horizon",
-		"traceTitle": "Advanced: original decision trace",
-		"traceLoading": "The plan is ready; its decision trace is still loading…",
-		"traceReady": "The plan is ready and its decision trace has loaded.",
-		"traceUnavailable": "No decision trace is available for this result.",
-		"phases": "Trace phases",
-		"firstPhase": "First phase",
-		"previousPhase": "Previous phase",
-		"nextPhase": "Next phase",
-		"lastPhase": "Last phase",
-		"decisions": "Atomic decisions",
-		"firstDecision": "First decision",
-		"previousDecision": "Previous decision",
-		"nextDecision": "Next decision",
-		"lastDecision": "Last decision",
-		"replay": "Decision state",
-		"before": "Before",
-		"after": "After",
-		"finalPlan": "Final plan",
-		"dates": "Dates",
-		"candidates": "Candidates",
-		"previousCandidates": "Previous candidate page",
-		"nextCandidates": "Next candidate page",
-		"page": "Page",
-		"compareAlternatives": "Compare this candidate across the horizon",
-		"deltas": "State changes",
-		"activations": "earned activations",
-		"noDecisions": "This phase recorded no atomic decision.",
-		"traceStatuses": {
-			"chosen": "Chosen",
-			"evaluated-rejected": "Evaluated and rejected",
-			"pruned": "Pruned",
-			"not-examined": "Not examined",
-			"ineligible": "Ineligible"
-		},
-		"tracePhaseStatuses": {
-			"completed": "Completed",
-			"interrupted": "Interrupted",
-			"not-run": "Not run"
-		},
-		"traceChanges": {
-			"added": "Added by this decision",
-			"moved-from": "Moved from this date",
-			"moved-to": "Moved to this date",
-			"removed": "Removed by this decision",
-			"shared": "Shared by this decision",
-			"unchanged": "Unchanged by this decision"
-		},
 		"calendarHelp": "Select a leave day to see its contribution to your plan.",
 		"explanationHelp": "See the break you get and what each day changes.",
-		"traceHelp": "Explore the calculation, decision by decision.",
 		"technicalDetails": "Calculation details",
 		"compareDates": "Compare other dates",
 		"stopComparing": "Close date comparison",
-		"replayNotice": "You are viewing a calculation step.",
 		"explanation": {
 			"breakTitle": "Your break",
 			"leaveDays": "leave days used",
@@ -328,9 +263,6 @@
 			"alternative": "With this date",
 			"sameDate": "This is the planned date. Choose another date above to see the difference.",
 			"moveHelp": "Try moving this one day. All other leave dates stay the same.",
-			"traceHelp": "Test this candidate against the state before its original decision.",
-			"beforeDecision": "Before this decision",
-			"withCandidate": "With this candidate",
 			"comparisonUnavailable": "The comparison for the original date is unavailable, so the change cannot be shown.",
 			"objectives": {
 				"obligation-validity": {
@@ -407,10 +339,6 @@
 			"expires": "Expires on",
 			"criteria": "The planner’s priorities",
 			"criteriaHelp": "Read from top to bottom: the first difference takes priority. Select a criterion to see how it is calculated.",
-			"traceImpactTitle": "Full-plan effect of this branch",
-			"traceImpactHelp": "These values compare the complete state before and after this branch. They show its impact; they do not explain why the planner chose it.",
-			"traceStageTitle": "Actual stage comparison",
-			"traceStageHelp": "These raw values were compared at this decision; the first difference explains the candidate’s status. The full-plan table below shows the effect after this choice.",
 			"firstDifference": "First difference",
 			"higher": "Higher is better",
 			"lower": "Lower is better",
@@ -431,7 +359,6 @@
 		},
 		"comparison": {
 			"title": "Compare dates",
-			"candidate": "Candidate date",
 			"preview": "Preview only. Your plan stays unchanged.",
 			"nearby": "Nearby available dates",
 			"noAlternatives": "No other date can use this leave day. You can still check a date to see why.",
@@ -441,8 +368,7 @@
 			"changes": "What would change",
 			"available": "Available date",
 			"unavailable": "This date can’t be used",
-			"backToPlan": "Back to my plan",
+			"backToPlan": "Back to my plan"
-			"backToTrace": "Back to the calculation"
 		}
 	},
 	"benchmark": {

src/i18n/es.json

@@ -34,25 +34,15 @@
 		"daySuffix": "día",
 		"daysSuffix": "días",
 		"expires": "exp.",
-		"remainingWhy": "Ver por qué",
 		"remainingValidity": "Utilizable del {available} al {expiry}.",
 		"remainingHorizon": "Plan calculado del {start} al {end}.",
 		"remainingEarnedFrom": "Permiso obtenido gracias a la regla «{rule}».",
-		"remainingHistoryHelp": "Estas fechas se examinaron realmente durante el cálculo. Los valores comparan cada intento con su estado inicial; el plan final puede ser diferente.",
-		"remainingNoEvaluations": "No se registró ningún intento atribuible a este saldo. Su categoría de caducidad por sí sola no explica por qué sigue sin utilizarse.",
 		"remainingSuggestions": {
 			"available-after-horizon": "Puedes ampliar el período planificado más allá de su fecha de disponibilidad y volver a calcular.",
 			"no-working-date": "Comprueba el período planificado y las fechas de validez de este saldo.",
 			"all-dates-occupied": "Puedes ampliar el período si la validez lo permite, o ajustar los días ya reservados y tus reglas, y volver a calcular.",
 			"preserved": "No es necesario hacer nada. Para solicitar su uso, añade una regla dentro de su período de validez y vuelve a calcular.",
 			"calculation-incomplete": "Repite el cálculo si quieres que termine la planificación."
-		},
-		"remainingCandidateReasons": {
-			"quality-no-improvement": "Esta opción no se seleccionó en esta fase del cálculo.",
-			"quality-protected-objective": "Esta opción empeoraría una prioridad que debe conservarse.",
-			"quality-outperformed": "El cálculo encontró después una opción mejor clasificada.",
-			"earned-entitlement-order": "Esta opción no respeta las fechas de disponibilidad de los permisos obtenidos.",
-			"unknown": "El motivo preciso de este intento no está disponible."
 		}
 	},
 	"dayTypes": {
@@ -218,7 +208,6 @@
 		"placementNavigation": "Navegación por las explicaciones de las asignaciones",
 		"placement": "Día de permiso",
 		"placements": "asignaciones",
-		"decision": "Decisión",
 		"of": "de",
 		"first": "Primera asignación",
 		"previous": "Asignación anterior",
@@ -231,13 +220,8 @@
 		"counterfactualReady": "Las fechas alternativas están listas.",
 		"counterfactualError": "No se pudieron calcular las fechas alternativas.",
 		"retryCounterfactual": "Reintentar el análisis de fechas",
-		"historicalEligibilityLoading": "Comprobando qué fechas podía usar este permiso…",
-		"historicalEligibilityReady": "La elegibilidad histórica de las fechas está lista.",
-		"historicalEligibilityError": "No se pudo comprobar la elegibilidad histórica de las fechas.",
-		"retryHistoricalEligibility": "Reintentar la comprobación de elegibilidad",
 		"eligible": "Válida",
 		"ineligible": "No válida",
-		"historical": "Estado de la búsqueda original",
 		"reason": "Motivo",
 		"explanationError": "No se pudo generar la explicación.",
 		"conflictDetails": "Por qué ningún plan satisface las obligaciones",
@@ -251,60 +235,11 @@
 		"currentPlacement": "Asignación explicada actualmente",
 		"explainedPeriod": "Período de descanso explicado",
 		"outsideHorizon": "Fecha de contexto fuera del horizonte de planificación",
-		"traceTitle": "Avanzado: traza de decisiones original",
-		"traceLoading": "El plan está listo; su traza de decisiones aún se está cargando…",
-		"traceReady": "El plan está listo y se ha cargado su traza de decisiones.",
-		"traceUnavailable": "No hay una traza de decisiones disponible para este resultado.",
-		"phases": "Fases de la traza",
-		"firstPhase": "Primera fase",
-		"previousPhase": "Fase anterior",
-		"nextPhase": "Fase siguiente",
-		"lastPhase": "Última fase",
-		"decisions": "Decisiones atómicas",
-		"firstDecision": "Primera decisión",
-		"previousDecision": "Decisión anterior",
-		"nextDecision": "Decisión siguiente",
-		"lastDecision": "Última decisión",
-		"replay": "Estado de la decisión",
-		"before": "Antes",
-		"after": "Después",
-		"finalPlan": "Plan final",
-		"dates": "Fechas",
-		"candidates": "Candidatos",
-		"previousCandidates": "Página de candidatos anterior",
-		"nextCandidates": "Página de candidatos siguiente",
-		"page": "Página",
-		"compareAlternatives": "Comparar este candidato en todo el horizonte",
-		"deltas": "Cambios de estado",
-		"activations": "activaciones obtenidas",
-		"noDecisions": "Esta fase no registró ninguna decisión atómica.",
-		"traceStatuses": {
-			"chosen": "Elegido",
-			"evaluated-rejected": "Evaluado y rechazado",
-			"pruned": "Podado",
-			"not-examined": "No examinado",
-			"ineligible": "No válido"
-		},
-		"tracePhaseStatuses": {
-			"completed": "Completada",
-			"interrupted": "Interrumpida",
-			"not-run": "No ejecutada"
-		},
-		"traceChanges": {
-			"added": "Añadido por esta decisión",
-			"moved-from": "Movido desde esta fecha",
-			"moved-to": "Movido a esta fecha",
-			"removed": "Eliminado por esta decisión",
-			"shared": "Compartido por esta decisión",
-			"unchanged": "Sin cambios por esta decisión"
-		},
 		"calendarHelp": "Selecciona un día de permiso para ver su aportación al plan.",
 		"explanationHelp": "Consulta tu descanso y qué cambia con cada día.",
-		"traceHelp": "Explora el cálculo, decisión a decisión.",
 		"technicalDetails": "Detalles del cálculo",
 		"compareDates": "Comparar otras fechas",
 		"stopComparing": "Cerrar comparación",
-		"replayNotice": "Estás viendo un paso del cálculo.",
 		"explanation": {
 			"breakTitle": "Tu descanso",
 			"leaveDays": "días de permiso usados",
@@ -328,9 +263,6 @@
 			"alternative": "Con esta fecha",
 			"sameDate": "Esta es la fecha prevista. Elige otra fecha arriba para ver la diferencia.",
 			"moveHelp": "Prueba a mover este día. Las demás fechas de permiso no cambian.",
-			"traceHelp": "Compara este candidato con el estado anterior a su decisión original.",
-			"beforeDecision": "Antes de esta decisión",
-			"withCandidate": "Con este candidato",
 			"comparisonUnavailable": "La comparación de la fecha original no está disponible, por lo que no se puede mostrar el cambio.",
 			"objectives": {
 				"obligation-validity": {
@@ -407,10 +339,6 @@
 			"expires": "Vence el",
 			"criteria": "Las prioridades del cálculo",
 			"criteriaHelp": "Lee de arriba abajo: la primera diferencia tiene prioridad. Selecciona un criterio para ver cómo se calcula.",
-			"traceImpactTitle": "Efecto de esta rama en el plan completo",
-			"traceImpactHelp": "Estos valores comparan el estado completo antes y después de esta rama. Muestran su efecto, no por qué el planificador la eligió.",
-			"traceStageTitle": "Comparación real en esta etapa",
-			"traceStageHelp": "Estos valores brutos se compararon en esta decisión; la primera diferencia explica el estado de la opción. La tabla del plan completo muestra el efecto de esta elección.",
 			"firstDifference": "Primera diferencia",
 			"higher": "Más es mejor",
 			"lower": "Menos es mejor",
@@ -431,7 +359,6 @@
 		},
 		"comparison": {
 			"title": "Comparar fechas",
-			"candidate": "Fecha del candidato",
 			"preview": "Solo una vista previa. Tu plan no cambia.",
 			"nearby": "Fechas cercanas disponibles",
 			"noAlternatives": "No hay otra fecha disponible para este día de permiso. Puedes comprobar una fecha para ver el motivo.",
@@ -441,8 +368,7 @@
 			"changes": "Qué cambiaría",
 			"available": "Fecha disponible",
 			"unavailable": "Esta fecha no se puede usar",
-			"backToPlan": "Volver a mi plan",
+			"backToPlan": "Volver a mi plan"
-			"backToTrace": "Volver al cálculo"
 		}
 	},
 	"benchmark": {

src/i18n/fr.json

@@ -34,25 +34,15 @@
 		"daySuffix": "jour",
 		"daysSuffix": "jours",
 		"expires": "exp.",
-		"remainingWhy": "Voir pourquoi",
 		"remainingValidity": "Utilisable du {available} au {expiry}.",
 		"remainingHorizon": "Planning calculé du {start} au {end}.",
 		"remainingEarnedFrom": "Congés gagnés grâce à la règle « {rule} ».",
-		"remainingHistoryHelp": "Ces dates ont réellement été examinées pendant le calcul. Les valeurs comparent chaque essai à son état de départ ; le planning final peut être différent.",
-		"remainingNoEvaluations": "Aucun essai attribuable à ce solde n’a été enregistré. La catégorie d’expiration ne suffit pas à expliquer pourquoi il reste inutilisé.",
 		"remainingSuggestions": {
 			"available-after-horizon": "Vous pouvez prolonger la période planifiée au-delà de sa date de disponibilité, puis recalculer.",
 			"no-working-date": "Vérifiez la période planifiée et les dates de validité de ce solde.",
 			"all-dates-occupied": "Vous pouvez élargir la période si la validité le permet, ou ajuster vos jours déjà posés et vos règles, puis recalculer.",
 			"preserved": "Aucune action nécessaire. Pour demander son utilisation, ajoutez une règle sur une période où il est utilisable, puis recalculez.",
 			"calculation-incomplete": "Relancez le calcul si vous souhaitez qu’il termine la planification."
-		},
-		"remainingCandidateReasons": {
-			"quality-no-improvement": "Cette possibilité n’a pas été retenue à cette étape du calcul.",
-			"quality-protected-objective": "Cette possibilité dégraderait une priorité à préserver.",
-			"quality-outperformed": "Le calcul a ensuite trouvé une possibilité mieux classée.",
-			"earned-entitlement-order": "Cette possibilité ne respecte pas les dates de disponibilité des congés gagnés.",
-			"unknown": "La raison précise de cet essai n’est pas disponible."
 		}
 	},
 	"dayTypes": {
@@ -218,7 +208,6 @@
 		"placementNavigation": "Navigation entre les explications des placements",
 		"placement": "Jour de congé",
 		"placements": "placements",
-		"decision": "Décision",
 		"of": "sur",
 		"first": "Premier placement",
 		"previous": "Placement précédent",
@@ -231,13 +220,8 @@
 		"counterfactualReady": "Les dates alternatives sont prêtes.",
 		"counterfactualError": "Les dates alternatives n’ont pas pu être calculées.",
 		"retryCounterfactual": "Relancer l’analyse des dates",
-		"historicalEligibilityLoading": "Vérification des dates utilisables pour ce congé…",
-		"historicalEligibilityReady": "L’éligibilité historique des dates est prête.",
-		"historicalEligibilityError": "L’éligibilité historique des dates n’a pas pu être vérifiée.",
-		"retryHistoricalEligibility": "Revérifier l’éligibilité historique",
 		"eligible": "Éligible",
 		"ineligible": "Inéligible",
-		"historical": "Statut de la recherche originale",
 		"reason": "Raison",
 		"explanationError": "L’explication n’a pas pu être produite.",
 		"conflictDetails": "Pourquoi aucun plan ne satisfait les obligations",
@@ -251,60 +235,11 @@
 		"currentPlacement": "Placement expliqué actuellement",
 		"explainedPeriod": "Période de repos expliquée",
 		"outsideHorizon": "Date de contexte hors de l’horizon de planification",
-		"traceTitle": "Avancé : trace des décisions originales",
-		"traceLoading": "Le plan est prêt ; sa trace de décision est encore en cours de chargement…",
-		"traceReady": "Le plan est prêt et sa trace de décision est chargée.",
-		"traceUnavailable": "Aucune trace de décision n’est disponible pour ce résultat.",
-		"phases": "Phases de la trace",
-		"firstPhase": "Première phase",
-		"previousPhase": "Phase précédente",
-		"nextPhase": "Phase suivante",
-		"lastPhase": "Dernière phase",
-		"decisions": "Décisions atomiques",
-		"firstDecision": "Première décision",
-		"previousDecision": "Décision précédente",
-		"nextDecision": "Décision suivante",
-		"lastDecision": "Dernière décision",
-		"replay": "État de la décision",
-		"before": "Avant",
-		"after": "Après",
-		"finalPlan": "Plan final",
-		"dates": "Dates",
-		"candidates": "Candidats",
-		"previousCandidates": "Page de candidats précédente",
-		"nextCandidates": "Page de candidats suivante",
-		"page": "Page",
-		"compareAlternatives": "Comparer ce candidat sur tout l’horizon",
-		"deltas": "Changements d’état",
-		"activations": "activations acquises",
-		"noDecisions": "Cette phase n’a enregistré aucune décision atomique.",
-		"traceStatuses": {
-			"chosen": "Choisi",
-			"evaluated-rejected": "Évalué et rejeté",
-			"pruned": "Élagué",
-			"not-examined": "Non examiné",
-			"ineligible": "Inéligible"
-		},
-		"tracePhaseStatuses": {
-			"completed": "Terminée",
-			"interrupted": "Interrompue",
-			"not-run": "Non exécutée"
-		},
-		"traceChanges": {
-			"added": "Ajouté par cette décision",
-			"moved-from": "Déplacé depuis cette date",
-			"moved-to": "Déplacé vers cette date",
-			"removed": "Retiré par cette décision",
-			"shared": "Partagé par cette décision",
-			"unchanged": "Inchangé par cette décision"
-		},
 		"calendarHelp": "Sélectionnez un jour de congé pour voir son apport au planning.",
 		"explanationHelp": "Découvrez votre pause et ce que chaque jour change.",
-		"traceHelp": "Explorez le calcul, décision par décision.",
 		"technicalDetails": "Détails du calcul",
 		"compareDates": "Comparer d’autres dates",
 		"stopComparing": "Fermer la comparaison",
-		"replayNotice": "Vous consultez une étape du calcul.",
 		"explanation": {
 			"breakTitle": "Votre pause",
 			"leaveDays": "jours de congé posés",
@@ -328,9 +263,6 @@
 			"alternative": "Avec cette date",
 			"sameDate": "C’est la date prévue. Choisissez une autre date ci-dessus pour voir la différence.",
 			"moveHelp": "Essayez de déplacer ce jour. Les autres dates de congé restent identiques.",
-			"traceHelp": "Testez ce candidat par rapport à l’état précédant sa décision d’origine.",
-			"beforeDecision": "Avant cette décision",
-			"withCandidate": "Avec ce candidat",
 			"comparisonUnavailable": "La comparaison pour la date initiale est indisponible ; la différence ne peut donc pas être affichée.",
 			"objectives": {
 				"obligation-validity": {
@@ -407,10 +339,6 @@
 			"expires": "Expire le",
 			"criteria": "Les priorités du calcul",
 			"criteriaHelp": "Lisez de haut en bas : la première différence est prioritaire. Sélectionnez un critère pour comprendre son calcul.",
-			"traceImpactTitle": "Effet de cette branche sur le plan complet",
-			"traceImpactHelp": "Ces valeurs comparent l’état complet avant et après cette branche. Elles montrent son effet, pas pourquoi le calcul l’a choisie.",
-			"traceStageTitle": "Comparaison réelle à cette étape",
-			"traceStageHelp": "Ces valeurs brutes ont été comparées lors de cette décision ; la première différence explique le statut de la possibilité. Le tableau du plan complet ci-dessous montre l’effet de ce choix.",
 			"firstDifference": "Première différence",
 			"higher": "Plus, c’est mieux",
 			"lower": "Moins, c’est mieux",
@@ -431,7 +359,6 @@
 		},
 		"comparison": {
 			"title": "Comparer les dates",
-			"candidate": "Date du candidat",
 			"preview": "Simulation uniquement. Votre planning reste inchangé.",
 			"nearby": "Dates proches disponibles",
 			"noAlternatives": "Aucune autre date ne permet de poser ce jour. Vous pouvez vérifier une date pour comprendre pourquoi.",
@@ -441,8 +368,7 @@
 			"changes": "Ce qui changerait",
 			"available": "Date disponible",
 			"unavailable": "Cette date ne peut pas être utilisée",
-			"backToPlan": "Revenir à mon planning",
+			"backToPlan": "Revenir à mon planning"
-			"backToTrace": "Revenir au calcul"
 		}
 	},
 	"benchmark": {