refactor(planning): remove the unused remaining-balance mirror

The summary and details already read the displayed plan's remaining
balances, so the writable mirror, its legacy conversion and the VacDay
classification/reason fields it alone populated are removed.

Refs #274

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

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

@@ -474,7 +474,7 @@ describe('CalendarYear planning outcome boundary', () => {
 			fixture.detectChanges();
 			const before = {
 				balances: structuredClone(input.vacationNumberSignal()),
-				remaining: structuredClone(input.remainingVacationDaysSignal()),
+				displayed: structuredClone(input.displayedPlanSignal()),
 				declarations: structuredClone(input.declaredDaysSignal()),
 				rules: structuredClone(rules.rules),
 			};
@@ -508,7 +508,7 @@ describe('CalendarYear planning outcome boundary', () => {
 			expect(dialog.textContent?.includes('Partial plan')).toBe(partial);
 			expect(input.planningOutcomeSignal()).toBe(outcome);
 			expect(input.vacationNumberSignal()).toEqual(before.balances);
-			expect(input.remainingVacationDaysSignal()).toEqual(before.remaining);
+			expect(input.displayedPlanSignal()).toEqual(before.displayed);
 			expect(input.declaredDaysSignal()).toEqual(before.declarations);
 			expect(rules.rules).toEqual(before.rules);
 			expect(calendar.createPlanningCalculation).toHaveBeenCalledOnce();
@@ -2164,19 +2164,11 @@ describe('CalendarYear planning outcome boundary', () => {
 			],
 		}).compileComponents();
 		const userInput = TestBed.inject(UserInputService);
-		userInput.remainingVacationDaysSignal.set([
-			{
-				id: 'stale',
-				type: SelectableDayType.CP,
-				numberOfDays: 1,
-				expiryDate: new Date('2025-01-01'),
-			},
-		]);
 		const fixture: ComponentFixture<CalendarYear> = TestBed.createComponent(CalendarYear);
 		fixture.detectChanges();
 		await fixture.whenStable();
 
-		expect(userInput.remainingVacationDaysSignal()).toEqual([]);
+		expect(userInput.displayedPlanSignal()).toBeUndefined();
 	});
 
 	it('keeps and summarizes a returned result', async () => {
@@ -2189,13 +2181,12 @@ describe('CalendarYear planning outcome boundary', () => {
 			],
 		}).compileComponents();
 		const userInput = TestBed.inject(UserInputService);
-		userInput.remainingVacationDaysSignal.set([]);
 		const fixture = TestBed.createComponent(CalendarYear);
 		fixture.detectChanges();
 		await fixture.whenStable();
 		await new Promise<void>((resolve) => setTimeout(resolve, 0));
 		fixture.detectChanges();
-		expect(userInput.remainingVacationDaysSignal()).toEqual([]);
+		expect(userInput.displayedPlanSignal()?.remainingBalances).toEqual(plan.remainingBalances);
 		const summaryValues = Array.from(
 			fixture.nativeElement.querySelectorAll('.plan-summary dd') as NodeListOf<HTMLElement>,
 		).map((element) => element.textContent?.trim());
@@ -2969,14 +2960,6 @@ describe('CalendarYear planning outcome boundary', () => {
 			],
 		}).compileComponents();
 		const userInput = TestBed.inject(UserInputService);
-		userInput.remainingVacationDaysSignal.set([
-			{
-				id: 'stale',
-				type: SelectableDayType.CP,
-				numberOfDays: 1,
-				expiryDate: new Date('2025-01-01'),
-			},
-		]);
 		const fixture = TestBed.createComponent(CalendarYear);
 		fixture.detectChanges();
 		await fixture.whenStable();
@@ -2988,6 +2971,6 @@ describe('CalendarYear planning outcome boundary', () => {
 		if (outcome?.kind === 'PlanningIncomplete')
 			expect(outcome.reasons[0].code).toBe('planner-error');
 		expect(fixture.componentInstance['isLoading']()).toBe(false);
-		expect(userInput.remainingVacationDaysSignal()).toEqual([]);
+		expect(userInput.displayedPlanSignal()).toBeUndefined();
 	});
 });

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

@@ -37,8 +37,6 @@ import {
 	CalendarService,
 	calendarProjectionHorizon,
 	SelectedDates,
-	SelectableDayType,
-	VacDay,
 } from '../../services/calendar-service';
 import { TranslationService } from '../../services/translation-service';
 import { UserInputService } from '../../services/user-input-service';
@@ -50,7 +48,6 @@ import {
 	LeaveType,
 	DeclaredNonWorkingDay,
 	PlanExplanation,
-	PlanOutcome,
 	PlanningCalculationContext,
 	PlanningExplanation,
 	PlanningObjective,
@@ -467,7 +464,6 @@ export class CalendarYear {
 		this.planDetailsOpen.set(false);
 		this.clearCounterfactual();
 		this.selectedDates.set(this.calendarService.getSelectedDatesForHorizon(horizon));
-		this.userInput.remainingVacationDaysSignal.set([]);
 	}
 
 	private loadArtifacts(calculation: PlanningCalculationContext): void {
@@ -517,13 +513,11 @@ export class CalendarYear {
 		if (plan) {
 			this.planningHorizon.set(plan.horizon);
 			this.selectedDates.set(this.calendarService.selectedDatesForPlan(plan));
-			this.userInput.remainingVacationDaysSignal.set(this.toLegacyBalances(plan));
 			return;
 		}
 		this.selectedDates.set(
 			this.calendarService.getSelectedDatesForHorizon(this.planningHorizon()!),
 		);
-		this.userInput.remainingVacationDaysSignal.set([]);
 	}
 
 	protected formatStatistic(value: number | null): string {
@@ -1078,16 +1072,4 @@ export class CalendarYear {
 		if (stage === 'dates') return 98;
 		return this.loadingProgress();
 	}
-
-	private toLegacyBalances(plan: PlanOutcome): VacDay[] {
-		return plan.remainingBalances.map((balance) => ({
-			id: balance.id,
-			type: balance.type as SelectableDayType,
-			numberOfDays: balance.quantity,
-			availableDate: new Date(`${balance.availableFrom}T00:00:00`),
-			expiryDate: new Date(`${balance.expiryDate}T00:00:00`),
-			classification: balance.classification,
-			reason: balance.reason,
-		}));
-	}
 }

src/app/services/calendar-service.ts

@@ -10,9 +10,7 @@ import {
 	planLeave as planLeaveOperation,
 	LeaveType,
 	PlanOutcome,
-	PlanningReason,
 	PlanningStateSnapshot,
-	RemainingClassification,
 } from './leave-planner.service';
 import { addPlanningDays, addPlanningYears, planningDateInParis } from './planning-date';
 
@@ -255,8 +253,6 @@ export type VacDay = {
 	/** Legacy balances omit this value; the planner then uses the horizon start. */
 	availableDate?: Date;
 	expiryDate: Date;
-	classification?: RemainingClassification;
-	reason?: PlanningReason;
 };
 
 export type Week = (Date | null)[];

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

@@ -161,7 +161,6 @@ export class UserInputService {
 	readonly vacationNumberSignal = signal<VacDay[]>(
 		this.getSavedValues() ?? this.getInitialValues(),
 	);
-	readonly remainingVacationDaysSignal = signal<VacDay[]>([]);
 	readonly planningOutcomeSignal = signal<PlanningOutcome | null>(null);
 	readonly planningSnapshotSignal = signal<PlanningSnapshot | null>(null);
 	readonly displayedPlanSignal = computed(() => {