feat: enhance loading spinner with progress indication and add warnin… (#49)

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

* Update src/app/services/calendar-service.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

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

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

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

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Apply suggestions from code review

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Fix setTimeout async anti-pattern in calendar-year component (#50)

* Initial plan

* fix: replace setTimeout async anti-pattern with queueMicrotask and void

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

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

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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>

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

@@ -18,4 +18,9 @@ export class UserInputService {
 	}
 
 	readonly vacationNumberSignal = signal<VacationsNumber>(this.getInitialValues());
+	readonly remainingVacationDaysSignal = signal<VacationsNumber>({
+		cp: 0,
+		rtt: 0,
+		other: 0,
+	});
 }