fix: resolve permission toggle persistence, nudge terminology, and bulk action bugs (Bugs #2-5)

- Fix togglePermission() to always include all permission keys with false defaults
- Add migration to backfill null/empty Manager permissions with config defaults
- Rename nudge UI text from "Relance" to "Notification"/"Notifier" across 8 files
- Fix select-all checkbox and show checkboxes on all declaration rows
- Remove en_attente_client status restriction from BulkNotificationController

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

resources/js/pages/notifications/Index.vue

@@ -53,8 +53,8 @@ function getDescription(notification: AppNotification): string {
     switch (type) {
         case 'nudge':
             return sender
-                ? `Relance de ${sender} sur ${title}`
-                : `Relance sur ${title}`;
+                ? `Notification de ${sender} sur ${title}`
+                : `Notification sur ${title}`;
         case 'declaration_overdue':
             return `Déclaration en retard : ${title}`;
         case 'document_uploaded':