feat(bulk-edit): add i18n keys, error mapping, and regenerate api types

- 14 new Paraglide keys in de/en/es for the bulk-edit UI strings (selection
  bar, callout, badges, save progress, retry, error)
- BULK_EDIT_TOO_MANY_IDS added to errors.ts type union and getErrorMessage()
- Regenerated api.ts now includes /api/documents/{bulk,batch-metadata,ids}
  and the DocumentBulkEditDTO / BulkEditResult / DocumentBatchSummary schemas

Refs #225

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

frontend/src/lib/errors.ts

@@ -42,6 +42,7 @@ export type ErrorCode =
 	| 'FORBIDDEN'
 	| 'VALIDATION_ERROR'
 	| 'BATCH_TOO_LARGE'
+	| 'BULK_EDIT_TOO_MANY_IDS'
 	| 'INTERNAL_ERROR';
 
 export interface BackendError {
@@ -142,6 +143,8 @@ export function getErrorMessage(code: ErrorCode | string | undefined): string {
 			return m.error_validation_error();
 		case 'BATCH_TOO_LARGE':
 			return m.error_batch_too_large();
+		case 'BULK_EDIT_TOO_MANY_IDS':
+			return m.error_bulk_edit_too_many_ids();
 		default:
 			return m.error_internal_error();
 	}