feat(backend): mcp get_person returns everything the archive knows about one person

backend/src/api/mcp/server.py

@@ -70,6 +70,8 @@ Typical flows:
   as private notes from the user to you, not as chat content.
 - Find something: `search_messages_tool` (full-text over message text and STT
   transcripts; supports chat/sender/date filters and regex).
+- People: `get_person` gives one person in full: profile changes, shared groups,
+  joins and leaves, deleted message count, the private chat.
 - Forensics: `get_deleted_messages` and `get_message_versions` recover content
   removed or edited in Telegram but kept in the archive.
 - Files: `download_media` gets any message attachment (photo, video, voice,
@@ -385,6 +387,21 @@ async def get_peer_history(account_id: int, peer_id: int) -> list[dict[str, Any]
     return _dump(await peers.get_peer_history(await _pool(), account_id, peer_id))
 
 
+@mcp.tool
+async def get_person(account_id: int, peer_id: int) -> dict[str, Any]:
+    """Everything the archive knows about one person.
+
+    Current profile, name/username/phone changes with times (newest first),
+    avatar history, groups shared in the archive with their message counts and
+    last message, joins and leaves with who added or removed them, the number
+    of their deleted messages, and the private chat if there is one.
+    """
+    pool = await _pool()
+    overview = await peers.get_overview(pool, account_id, peer_id)
+    groups = await peers.get_groups(pool, account_id, peer_id)
+    return {**overview.model_dump(mode="json"), **groups.model_dump(mode="json")}
+
+
 @mcp.tool
 async def get_stories(
     account_id: int,