feat(i18n): add person_meta_doc_count + person_meta_rel_count keys (de/en/es) (§7)

Refs #859
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/messages/de.json

@@ -193,6 +193,8 @@
 	"person_no_docs": "Diese Person ist noch nicht als Absender verknüpft.",
 	"person_received_docs_heading": "Empfangene Dokumente",
 	"person_no_received_docs": "Diese Person ist noch nicht als Empfänger verknüpft.",
+	"person_meta_doc_count": "{count} Dokumente",
+	"person_meta_rel_count": "{count} Beziehungen",
 	"person_role_sender": "Gesendet",
 	"person_role_receiver": "Empfangen",
 	"person_co_correspondents_heading": "Häufige Korrespondenten",

frontend/messages/en.json

@@ -193,6 +193,8 @@
 	"person_no_docs": "This person has not yet been linked as a sender.",
 	"person_received_docs_heading": "Received documents",
 	"person_no_received_docs": "This person has not yet been linked as a receiver.",
+	"person_meta_doc_count": "{count} documents",
+	"person_meta_rel_count": "{count} relationships",
 	"person_role_sender": "Sent",
 	"person_role_receiver": "Received",
 	"person_co_correspondents_heading": "Frequent correspondents",

frontend/messages/es.json

@@ -193,6 +193,8 @@
 	"person_no_docs": "Esta persona aún no está vinculada como remitente.",
 	"person_received_docs_heading": "Documentos recibidos",
 	"person_no_received_docs": "Esta persona aún no está vinculada como receptor.",
+	"person_meta_doc_count": "{count} documentos",
+	"person_meta_rel_count": "{count} relaciones",
 	"person_role_sender": "Enviado",
 	"person_role_receiver": "Recibido",
 	"person_co_correspondents_heading": "Corresponsales frecuentes",