fix: category bulk-delete had no confirmation, single-delete used native dialogs

Bulk-delete called facade.applyBulkDelete() straight from the button
with zero confirmation. Single-delete had a confirm gate but via raw
window.confirm/alert instead of the themed dialog used elsewhere.

Migrated both to app-confirm-dialog (single + new bulk), and the
delete-blocked message to a themed app-dialog instead of window.alert.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/i18n/translations.ts

@@ -1557,6 +1557,8 @@ export interface Translations {
     saveDraft: string;
     publish: string;
     confirmDelete: string;
+    confirmBulkDelete: string;
+    deleteTitle: string;
     confirmLeaveUnsaved: string;
     deleteBlocked: string;
     emptyTitle: string;