refactor: enhance date handling across components

- Replaced direct date manipulations with utility functions for consistency and readability.
- Updated date formatting in `DailyCalendar`, `RecentTasks`, `CompletionRateChart`, and other components to use `formatDateShort` and `formatDateForDisplay`.
- Improved date parsing in `JiraLogs`, `JiraSchedulerConfig`, and `BackupSettingsPageClient` to ensure proper handling of date strings.
- Streamlined date initialization in `useDaily` and `DailyService` to utilize `getToday` and `getYesterday` for better clarity.

src/components/settings/GeneralSettingsPageClient.tsx

@@ -10,6 +10,7 @@ import { Input } from '@/components/ui/Input';
 import { TagForm } from '@/components/forms/TagForm';
 import { UserPreferencesProvider } from '@/contexts/UserPreferencesContext';
 import Link from 'next/link';
+import { formatDateForDisplay } from '@/lib/date-utils';
 
 interface GeneralSettingsPageClientProps {
   initialPreferences: UserPreferences;
@@ -294,7 +295,7 @@ export function GeneralSettingsPageClient({ initialPreferences, initialTags }: G
                                 </div>
                                 {('createdAt' in tag && (tag as Tag & { createdAt: Date }).createdAt) && (
                                   <div className="text-xs text-[var(--muted-foreground)]">
-                                    Créé le {new Date((tag as Tag & { createdAt: Date }).createdAt).toLocaleDateString('fr-FR')}
+                                    Créé le {formatDateForDisplay((tag as Tag & { createdAt: Date }).createdAt)}
                                   </div>
                                 )}
                               </div>