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/models/agent_llm_log.py

@@ -1,7 +1,7 @@
 """
 Agent LLM 调用日志模型 — 记录每次 Agent Runtime 发起的 LLM 调用
 """
-from sqlalchemy import Column, String, Text, Integer, DateTime, ForeignKey, func
+from sqlalchemy import Column, String, Text, Integer, DateTime, ForeignKey, Index, func
 from sqlalchemy.dialects.mysql import CHAR
 from app.core.database import Base
 import uuid
@@ -27,3 +27,11 @@ class AgentLLMLog(Base):
     status = Column(String(20), default="success", comment="状态: success/error")
     error_message = Column(Text, nullable=True, comment="错误信息")
     created_at = Column(DateTime, default=func.now(), comment="创建时间")
+
+    __table_args__ = (
+        Index("idx_llm_agent_id", "agent_id"),
+        Index("idx_llm_user_id", "user_id"),
+        Index("idx_llm_session_id", "session_id"),
+        Index("idx_llm_created_at", "created_at"),
+        Index("idx_llm_agent_created", "agent_id", "created_at"),
+    )