chore(i18n): remove orphaned error_person_rename_conflict translation key

errors.ts no longer references this code (the rename-propagation listener
was deleted) and the matching ErrorCode value is gone from the backend.
The Paraglide-compiled message helpers should not include strings nothing
calls — drop the entries from de/en/es to keep the i18n surface honest.

Felix #5615 + Elicit #5624 blocker.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/messages/de.json

@@ -551,7 +551,6 @@
 	"person_alias_btn_delete": "Entfernen",
 	"error_alias_not_found": "Der Namensalias wurde nicht gefunden.",
 	"error_invalid_person_type": "Der angegebene Personentyp ist ungültig.",
-	"error_person_rename_conflict": "Eine andere Bearbeitung hat einen verknüpften Transkriptionsblock gleichzeitig geändert. Bitte erneut versuchen.",
 	"validation_last_name_required": "Nachname ist Pflichtfeld.",
 	"validation_first_name_required": "Vorname ist Pflichtfeld.",
 	"error_ocr_service_unavailable": "Der OCR-Dienst ist nicht verfügbar.",

frontend/messages/en.json

@@ -551,7 +551,6 @@
 	"person_alias_btn_delete": "Remove",
 	"error_alias_not_found": "The name alias was not found.",
 	"error_invalid_person_type": "The specified person type is not valid.",
-	"error_person_rename_conflict": "Another edit modified a referenced transcription block at the same time. Please try again.",
 	"validation_last_name_required": "Last name is required.",
 	"validation_first_name_required": "First name is required.",
 	"error_ocr_service_unavailable": "The OCR service is not available.",

frontend/messages/es.json

@@ -551,7 +551,6 @@
 	"person_alias_btn_delete": "Eliminar",
 	"error_alias_not_found": "No se encontro el alias de nombre.",
 	"error_invalid_person_type": "El tipo de persona especificado no es válido.",
-	"error_person_rename_conflict": "Otra edición modificó un bloque de transcripción referenciado al mismo tiempo. Por favor, inténtalo de nuevo.",
 	"validation_last_name_required": "El apellido es obligatorio.",
 	"validation_first_name_required": "El nombre es obligatorio.",
 	"error_ocr_service_unavailable": "El servicio OCR no está disponible.",