feat: 实现用户画像、占卜历史与后端用户管理模块

backend/src/v1/agent/repository.py

@@ -335,6 +335,59 @@ class AgentRepository:
             return None
         return str(latest_id)
 
+    async def get_latest_assistant_messages_by_user_sessions(
+        self,
+        *,
+        user_id: str,
+        visibility_mask: int | None = None,
+        session_limit: int = 50,
+    ) -> list[dict[str, object]]:
+        try:
+            user_uuid = UUID(user_id)
+        except ValueError as exc:
+            raise ApiProblemError(
+                status_code=422,
+                code="AGENT_USER_ID_INVALID",
+                detail="Invalid user_id",
+            ) from exc
+
+        safe_limit = max(int(session_limit), 1)
+        session_stmt = (
+            select(AgentChatSession.id)
+            .where(AgentChatSession.user_id == user_uuid)
+            .where(AgentChatSession.deleted_at.is_(None))
+            .order_by(AgentChatSession.last_activity_at.desc())
+            .limit(safe_limit)
+        )
+        session_ids = (await self._session.execute(session_stmt)).scalars().all()
+        if not session_ids:
+            return []
+
+        snapshots: list[dict[str, object]] = []
+        for session_id in session_ids:
+            message_stmt = (
+                select(AgentChatMessage)
+                .where(AgentChatMessage.session_id == session_id)
+                .where(AgentChatMessage.deleted_at.is_(None))
+                .where(AgentChatMessage.role == AgentChatMessageRole.ASSISTANT)
+                .order_by(AgentChatMessage.created_at.desc())
+                .limit(1)
+            )
+            message_stmt = self._apply_visibility_filter(
+                stmt=message_stmt,
+                visibility_mask=visibility_mask,
+            )
+            message = (await self._session.execute(message_stmt)).scalar_one_or_none()
+            if message is None:
+                continue
+            snapshots.append(await self._to_snapshot_message(message))
+
+        snapshots.sort(
+            key=lambda item: str(item.get("timestamp") or ""),
+            reverse=True,
+        )
+        return snapshots
+
     async def get_system_agent_config(
         self, *, agent_type: str
     ) -> dict[str, object] | None: