feat(planning): make optimization rules composable

Evaluate explicit, ordered optimization configurations through one shared
planner model. Add six editable presets, durable one-time legacy migration,
and consistent completed and cancelled plan provenance.

Include functional regressions and the agreed trace-removal and benchmark
follow-up specs. Performance acceptance remains in #78 under unchanged gates.

Refs: #70, #71, #72, #73, #74, #75, #76, #77, #78

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

@@ -80,6 +80,7 @@ export type {
 	TimeOffPeriod,
 	TimeWindowContribution,
 	TimeWindowPlanningRule,
+	OptimizationPlanningRule,
 	TraceCounterfactualSelection,
 	TraceCandidateStatus,
 } from './leave-planner.core';
@@ -117,6 +118,7 @@ interface UntrustedRecord {
 	placement?: unknown;
 	rewardDays?: unknown;
 	rewardType?: unknown;
+	configuration?: unknown;
 }
 
 interface TransportSnapshot {
@@ -238,6 +240,12 @@ function snapshotRequest(request: unknown): TransportSnapshot {
 					enabled: value?.enabled,
 					force: value?.force,
 				};
+				if (
+					typeof value?.type === 'string' &&
+					value.type.toLowerCase() === 'optimization'
+				) {
+					return { ...base, configuration: cloneUnknown(value.configuration) };
+				}
 				if (typeof value?.type === 'string' && value.type.toLowerCase() === 'time_window') {
 					return {
 						...base,