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/execution_log.py

@@ -1,7 +1,7 @@
 """
 执行日志模型
 """
-from sqlalchemy import Column, String, Text, Integer, DateTime, JSON, ForeignKey, func
+from sqlalchemy import Column, String, Text, Integer, DateTime, JSON, ForeignKey, Index, func
 from sqlalchemy.dialects.mysql import CHAR
 from sqlalchemy.orm import relationship
 from app.core.database import Base
@@ -22,6 +22,13 @@ class ExecutionLog(Base):
     timestamp = Column(DateTime, default=func.now(), comment="时间戳")
     duration = Column(Integer, comment="执行耗时(ms)")
 
+    __table_args__ = (
+        Index("idx_exec_execution_id", "execution_id"),
+        Index("idx_exec_timestamp", "timestamp"),
+        Index("idx_exec_level", "level"),
+        Index("idx_exec_node_id", "node_id"),
+    )
+
     # 关系
     execution = relationship("Execution", backref="logs")