T hoguet/issue16 (#61)

* feat: enhance loading spinner with progress indication and add warning for unplaced vacation days

* feat: upgrade Angular dependencies to version 21 and implement new animation features

- Updated Angular dependencies in package.json to version 21.x.x.
- Added `provideAnimationsAsync` to app configuration for improved animation handling.
- Refactored user input component to utilize a dynamic list of vacation days with animations.
- Introduced a new `DayInput` component for managing individual vacation days.
- Enhanced styling and animations for user input and day input components.
- Updated calendar service to support new vacation day structure.
- Adjusted tests to accommodate changes in component structure and dependencies.

* feat: enhance vacation optimization logic and UI components

* Fix signal immutability violations and cleanup unused code (#62)

* Initial plan

* fix: address PR review comments for signal immutability and cleanup

Co-authored-by: THoguet <61246905+THoguet@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: THoguet <61246905+THoguet@users.noreply.github.com>

* fix: add --legacy-peer-deps for Angular 21 compatibility (#63)

* Initial plan

* fix: add --legacy-peer-deps to npm ci for Angular 21 compatibility

Co-authored-by: THoguet <61246905+THoguet@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: THoguet <61246905+THoguet@users.noreply.github.com>

* Fix unit tests for VacDay[] type migration (#64)

* Initial plan

* fix: update unit tests to match VacDay[] type structure

Co-authored-by: THoguet <61246905+THoguet@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: THoguet <61246905+THoguet@users.noreply.github.com>

---------

Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>

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

@@ -3,14 +3,14 @@ import { UserInputService } from '../../services/user-input-service';
 import { MatCard, MatCardContent } from '@angular/material/card';
 import { CalendarMonth } from '../calendar-month/calendar-month';
 import { CalendarService, SelectedDates } from '../../services/calendar-service';
-import { CommonModule } from '@angular/common';
+
 import { MatProgressSpinner } from '@angular/material/progress-spinner';
 import { CalendarSettingsService } from '../../services/calendar-settings-service';
 import { DateCacheService } from '../../services/date-cache.service';
 
 @Component({
 	selector: 'app-calendar-year',
-	imports: [MatCard, CalendarMonth, MatCardContent, CommonModule, MatProgressSpinner],
+	imports: [MatCard, CalendarMonth, MatCardContent, MatProgressSpinner],
 	templateUrl: './calendar-year.html',
 	styleUrl: './calendar-year.scss',
 })
@@ -45,9 +45,10 @@ export class CalendarYear {
 			queueMicrotask(() => {
 				void (async () => {
 					if (this.selectedDates) {
-						// Create a copy to avoid mutating the original signal data
+						// Create a deep copy to avoid mutating the original signal data
+						const vacationDaysCopy = vacationData.map((vd) => ({ ...vd }));
 						const remainingDays = await this.selectedDates.optimizeVacations(
-							{ ...vacationData },
+							vacationDaysCopy,
 							this.calendarSettingsService,
 							this.calendarService,
 							(progress: number) => {