feat: add 甜甜 Feishu bot for 苏瑶3号 knowledge-graph agent

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

backend/app/main.py

@@ -234,6 +234,13 @@ async def startup_event():
     except Exception as e:
         logger.error(f"苏瑶长连接启动失败: {e}")
 
+    # 启动甜甜飞书长连接（苏瑶3号）
+    try:
+        from app.services.tiantian_ws_handler import start_ws_client as start_tiantian_ws
+        asyncio.ensure_future(start_tiantian_ws())
+    except Exception as e:
+        logger.error(f"甜甜长连接启动失败: {e}")
+
 # 注册路由
 from app.api import auth, uploads, workflows, executions, websocket, execution_logs, data_sources, agents, platform_templates, model_configs, webhooks, template_market, batch_operations, collaboration, permissions, monitoring, alert_rules, node_test, node_templates, tools, agent_chat, agent_monitoring, knowledge_base, agent_schedules, notifications, feishu_bind