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

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

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

@@ -41,23 +41,25 @@ export class CalendarYear {
 			console.log('Optimizing vacations with data:', vacationData);
 			this.isLoading.set(true);
 			this.loadingProgress.set(0);
-			// Simulate server-side calculation with a small delay
-			setTimeout(async () => {
-				if (this.selectedDates) {
-					// Create a copy to avoid mutating the original signal data
-					const remainingDays = await this.selectedDates.optimizeVacations(
-						{ ...vacationData },
-						this.calendarSettingsService,
-						this.calendarService,
-						(progress: number) => {
-							this.loadingProgress.set(progress);
-						},
-					);
-					// Update the remaining vacation days signal
-					this.userInput.remainingVacationDaysSignal.set(remainingDays);
-				}
-				this.isLoading.set(false);
-			}, 1);
+			// Defer execution to allow UI to update
+			queueMicrotask(() => {
+				void (async () => {
+					if (this.selectedDates) {
+						// Create a copy to avoid mutating the original signal data
+						const remainingDays = await this.selectedDates.optimizeVacations(
+							{ ...vacationData },
+							this.calendarSettingsService,
+							this.calendarService,
+							(progress: number) => {
+								this.loadingProgress.set(progress);
+							},
+						);
+						// Update the remaining vacation days signal
+						this.userInput.remainingVacationDaysSignal.set(remainingDays);
+					}
+					this.isLoading.set(false);
+				})();
+			});
 		});
 	}