fix: improve date formatting and backup path handling

- Updated `formatTimeAgo` in `AdvancedSettingsPageClient` to use a fixed format for hydration consistency.
- Refined `formatDate` in `BackupSettingsPageClient` for consistent server/client formatting.
- Refactored `BackupService` to use `getCurrentBackupPath` for all backup path references, ensuring up-to-date paths and avoiding caching issues.
- Added `getCurrentBackupPath` method to dynamically retrieve the current backup path based on environment variables.

components/settings/BackupSettingsPageClient.tsx

@@ -158,7 +158,17 @@ export default function BackupSettingsPageClient({ initialData }: BackupSettings
   };
 
   const formatDate = (date: string | Date): string => {
-    return new Date(date).toLocaleString();
+    // Format cohérent serveur/client pour éviter les erreurs d'hydratation
+    const d = new Date(date);
+    return d.toLocaleDateString('fr-FR', {
+      day: '2-digit',
+      month: '2-digit', 
+      year: 'numeric',
+      hour: '2-digit',
+      minute: '2-digit',
+      second: '2-digit',
+      hour12: false
+    });
   };
 
   if (isLoading) {