feat: expose graph orchestration mode, fix pipeline multi-agent, add Feishu tools (Phase 3)

增强编排 + 飞书深度集成：
- Graph 模式：暴露 orchestrator._graph() 到 run() 方法，workflow_integration 支持 graph nodes/edges
- Pipeline 修复：多 Agent 按步骤轮转分配，不再只用 agents[0]
- 4个飞书操作工具: feishu_create_doc / feishu_create_calendar_event / feishu_search_contacts / feishu_send_approval
- 飞书 @mention→Goal：feishu/ orange WS handler 支持 "目标: xxx" 触发自动创建 Goal

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

backend/app/services/feishu_ws_handler.py

@@ -115,6 +115,27 @@ def _reply_card(open_id: str, title: str, content: str, status: str = "info"):
         logger.warning("飞书回复卡片失败: %s", e)
 
 
+async def _handle_goal_creation(db, user_id: str, goal_title: str, open_id: str):
+    """从飞书消息中创建 Goal 并异步启动执行。"""
+    from app.services.goal_service import create_goal
+    from app.tasks.goal_tasks import execute_goal_task
+
+    try:
+        goal = create_goal(db=db, creator_id=user_id, title=goal_title, priority=5)
+        _reply_to_feishu(open_id, f"✅ 目标已创建: **{goal.title}**\n正在分解任务并启动执行...")
+
+        # 异步执行目标
+        task = execute_goal_task.delay(str(goal.id))
+        logger.info("飞书触发 Goal 创建: goal_id=%s celery_task=%s", goal.id, task.id)
+
+        # 更新状态
+        from app.services.goal_service import update_goal
+        update_goal(db, str(goal.id), status="active")
+    except Exception as e:
+        logger.error("飞书 Goal 创建失败: %s", e)
+        _reply_to_feishu(open_id, f"创建目标失败: {e}")
+
+
 async def _handle_message_async(data):
     """异步处理飞书消息。"""
     open_id = _get_sender_open_id(data)
@@ -225,6 +246,22 @@ async def _handle_message_async(data):
             memory_scope_id=str(agent.id),
         )
 
+        # ── 目标/任务意图检测：创建 Goal 并异步执行 ──
+        goal_triggers = ["创建目标:", "目标:", "创建任务:", "new goal:", "goal:"]
+        triggered_goal = False
+        goal_title = ""
+        for trigger in goal_triggers:
+            if text.lower().startswith(trigger.lower()):
+                trigger_text = text[len(trigger):].strip()
+                if trigger_text:
+                    goal_title = trigger_text[:500]
+                    triggered_goal = True
+                break
+
+        if triggered_goal and goal_title:
+            await _handle_goal_creation(db, user.id, goal_title, open_id)
+            return
+
         on_llm_call = _make_llm_logger(db, agent_id=str(agent.id), user_id=user.id)
         runtime = AgentRuntime(config=config, on_llm_call=on_llm_call)
         result = await runtime.run(text)