fix: delete agent 500 error + dynamic personality + deployment guide

- Fix delete agent 500: clean up FK records (agent_llm_logs, permissions,
  schedules, executions, team_members) and unbind goals/tasks before delete
- Remove hardcoded personality templates in Android, replace with dynamic
  system prompt generation from name + description
- Set promptSectionsEnabled=false to bypass PromptComposer for personality
- Add Tencent Cloud Linux deployment guide (Docker Compose)
- Accumulated backend service updates, frontend UI fixes, Android app changes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/api/agent_market.py

@@ -45,7 +45,7 @@ class AgentMarketItem(BaseModel):
     use_count: int = 0
     view_count: int = 0
     version: int = 1
-    user_id: str
+    user_id: Optional[str] = None
     creator_username: Optional[str] = None
     is_favorited: Optional[bool] = None
     user_rating: Optional[int] = None
@@ -70,7 +70,7 @@ class AgentMarketDetail(BaseModel):
     use_count: int = 0
     view_count: int = 0
     version: int = 1
-    user_id: str
+    user_id: Optional[str] = None
     creator_username: Optional[str] = None
     is_favorited: Optional[bool] = None
     user_rating: Optional[int] = None
@@ -100,7 +100,7 @@ class RatingResponse(BaseModel):
     """评分响应"""
     id: str
     agent_id: str
-    user_id: str
+    user_id: Optional[str] = None
     username: Optional[str] = None
     rating: int
     comment: Optional[str] = None
@@ -137,7 +137,7 @@ def _build_agent_item(agent: Agent, current_user: Optional[User], db: Session) -
         "use_count": agent.use_count or 0,
         "view_count": agent.view_count or 0,
         "version": agent.version or 1,
-        "user_id": agent.user_id,
+        "user_id": agent.user_id or "",
         "creator_username": agent.user.username if agent.user else None,
         "is_favorited": None,
         "user_rating": None,