feat: 添加启动时自动执行数据库迁移

添加 migrate_single_agent_mode 函数，在系统启动时自动添加
single_agent_bot_id 字段到 agent_user 表

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

routes/bot_manager.py

@@ -1041,6 +1041,39 @@ async def migrate_add_marketplace_fields():
             logger.info("Marketplace fields migration completed")
 
 
+async def migrate_single_agent_mode():
+    """
+    添加单智能体模式相关字段到 agent_user 表
+    """
+    pool = get_db_pool_manager().pool
+
+    async with pool.connection() as conn:
+        async with conn.cursor() as cursor:
+            # 检查 single_agent_bot_id 字段是否存在
+            await cursor.execute("""
+                SELECT column_name
+                FROM information_schema.columns
+                WHERE table_name = 'agent_user' AND column_name = 'single_agent_bot_id'
+            """)
+            has_single_agent_bot_id = await cursor.fetchone()
+
+            if not has_single_agent_bot_id:
+                logger.info("Adding single_agent_bot_id column to agent_user table")
+                await cursor.execute("""
+                    ALTER TABLE agent_user
+                    ADD COLUMN single_agent_bot_id UUID
+                """)
+                await cursor.execute("""
+                    CREATE INDEX IF NOT EXISTS idx_agent_user_single_agent_bot
+                    ON agent_user(single_agent_bot_id) WHERE single_agent_bot_id IS NOT NULL
+                """)
+                logger.info("Single agent mode migration completed")
+            else:
+                logger.info("single_agent_bot_id column already exists")
+
+            await conn.commit()
+
+
 async def init_bot_manager_tables():
     """
     初始化 Bot Manager 相关的所有数据库表
@@ -1054,6 +1087,8 @@ async def init_bot_manager_tables():
     await migrate_bot_owner_and_shares()
     # 3. Marketplace 字段迁移
     await migrate_add_marketplace_fields()
+    # 4. Single Agent Mode 字段迁移
+    await migrate_single_agent_mode()
 
     # SQL 表创建语句
     tables_sql = [