feat(web): add auth+search i18n translations and filter-bar accessibility

Add missing auth and search translation namespaces to vi.json and en.json
that are required by login/register pages and search filter-bar component.
Update filter-bar with useTranslations('search'), aria-labels, and
role="search" for WCAG 2.1 AA compliance.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/modules/listings/domain/services/moderation.service.ts

@@ -1,3 +1,4 @@
+import { type ListingStatus } from '@prisma/client';
 import { type ListingEntity } from '../entities/listing.entity';
 
 export interface ModerationAction {
@@ -29,7 +30,7 @@ export class ModerationService {
    */
   applyStatusTransition(
     listing: ListingEntity,
-    newStatus: string,
+    newStatus: ListingStatus,
     moderationNotes?: string,
   ): void {
     if (newStatus === 'REJECTED' && moderationNotes) {