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/messages/es.json

@@ -873,5 +873,19 @@
 	"bulk_drop_zone_label": "Soltar archivos aquí",
 	"bulk_remove_file": "Eliminar",
 	"bulk_title_single": "Nuevo Documento",
-	"bulk_title_multi": "Nuevos Documentos"
+	"bulk_title_multi": "Nuevos Documentos",
+	"bulk_edit_button": "Edición masiva",
+	"bulk_edit_n_selected": "{count} documentos seleccionados",
+	"bulk_edit_clear_all": "Limpiar todo",
+	"bulk_edit_all_x": "Editar los {count}",
+	"bulk_edit_select_document": "Seleccionar documento {title}",
+	"bulk_edit_hint": "Solo se aplican los campos rellenados. Las etiquetas y los destinatarios se añaden, no se reemplazan.",
+	"bulk_edit_badge_additive": "+ se añade",
+	"bulk_edit_badge_replace": "se reemplaza",
+	"bulk_edit_save_progress": "Lote {done} de {total} procesado",
+	"bulk_edit_save_partial": "{done} de {total} guardado",
+	"bulk_edit_retry": "Reintentar",
+	"bulk_edit_title": "Edición masiva",
+	"bulk_edit_save_button": "Aplicar",
+	"error_bulk_edit_too_many_ids": "Máximo 500 documentos por solicitud."
 }