feat: add PlanningDurationService for estimating planning duration

- Implemented PlanningDurationService to provide an indicative wait time before calculation based on user input and calendar settings.
- Introduced duration estimation logic that considers horizon dates, balances, and rules without triggering a calculation.
- Enhanced user input component to display estimated duration using the new service.
- Updated translation files to include new duration estimate strings in multiple languages.
- Added tests for PlanningDurationService to ensure accurate duration estimation and calibration.
- Refactored leave planner service to remove hardcoded deadlines and improve worker responsiveness.

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

@@ -59,7 +59,7 @@ export interface PlanningRequest {
 	identities?: unknown;
 	/** Optional caller-owned human-readable labels copied into a calculation snapshot. */
 	labels?: unknown;
-	/** A testable deadline in milliseconds. The production default is ten seconds. */
+	/** Opt-in planning-work budget in milliseconds; omitted means run until completion or cancellation. */
 	deadlineMs?: number;
 	progress?: (stage: string) => void;
 }
@@ -1235,8 +1235,6 @@ class UserCancelled extends Error {}
 type PlanningSteps<T> = Generator<boolean | undefined, T, void>;
 
 const DAY_MS = 86_400_000;
-const MAX_PLANNING_MS = 10_000;
-const CORE_DEADLINE_MARGIN_MS = 50;
 // ponytail: cap the number of feasible obligation branches previewed for a
 // loaded year; replace with bounded branch-and-bound if mobile evidence shows
 // that this ceiling misses a better lexicographic assignment.
@@ -5735,14 +5733,8 @@ function* calculatePlanningSteps(
 		calendar;
 	const started =
 		typeof performance !== 'undefined' && performance.now ? performance.now() : Date.now();
-	const configuredLimit =
-		typeof source.deadlineMs === 'number' ? source.deadlineMs : MAX_PLANNING_MS;
-	const deadline = Math.min(Math.max(0, configuredLimit), MAX_PLANNING_MS);
-	// Leave a small scheduling margin so the synchronous SSR/test fallback also
-	// observes the public ten-second wall-clock ceiling; browser workers have a
-	// separate watchdog in planInWorker.
-	const coreDeadline =
-		deadline === MAX_PLANNING_MS ? deadline - CORE_DEADLINE_MARGIN_MS : deadline;
+	const deadline =
+		typeof source.deadlineMs === 'number' ? source.deadlineMs : Number.POSITIVE_INFINITY;
 	const context = {
 		horizon,
 		holidays,
@@ -5754,7 +5746,7 @@ function* calculatePlanningSteps(
 		workingDays,
 		initialBalances: normalized.balances,
 		rules: normalized.rules,
-		deadline: coreDeadline,
+		deadline,
 		started,
 		request: source,
 		nodes: 0,