```

feat(feishu): 添加飞书长连接支持并重构事件处理

添加了 FeishuEventService 来统一处理飞书消息事件，
新增 long_connection.py 实现长连接客户端，
修改 webhook 路由使用新的事件处理服务，
添加了 lark-oapi 依赖支持长连接功能，
更新测试用例覆盖新的事件处理逻辑。

BREAKING CHANGE: 飞书事件处理逻辑重构，统一使用
FeishuEventService 进行消息处理和审计记录。
```

app/modules/feishu/long_connection.py

@@ -0,0 +1,79 @@
+import json
+import logging
+from typing import Any
+from urllib.parse import urlsplit
+
+from app.core.config import get_settings
+from app.core.database import SessionLocal
+from app.modules.feishu.events import FeishuEventService
+
+logger = logging.getLogger(__name__)
+
+
+def _sdk_domain(base_url: str) -> str:
+    parsed = urlsplit(base_url)
+    if not parsed.scheme or not parsed.netloc:
+        return "https://open.feishu.cn"
+    return f"{parsed.scheme}://{parsed.netloc}"
+
+
+def _sdk_event_to_payload(event: Any) -> dict[str, Any]:
+    try:
+        from lark_oapi.core.json import JSON
+    except ImportError as exc:
+        raise RuntimeError("lark-oapi is required for Feishu long connection") from exc
+
+    data = JSON.marshal(event)
+    if not data:
+        return {}
+    return json.loads(data)
+
+
+def _handle_message_event(event: Any) -> None:
+    payload = _sdk_event_to_payload(event)
+    db = SessionLocal()
+    try:
+        result = FeishuEventService(db).handle_event(
+            payload,
+            source="long_connection",
+            auto_reply=True,
+        )
+        logger.info("Handled Feishu long connection event: %s", result)
+    finally:
+        db.close()
+
+
+def run_long_connection() -> None:
+    """Start the Feishu long connection client and block forever."""
+
+    settings = get_settings()
+    if not settings.feishu_app_id or not settings.feishu_app_secret:
+        raise RuntimeError("FEISHU_APP_ID and FEISHU_APP_SECRET are required")
+
+    try:
+        import lark_oapi as lark
+    except ImportError as exc:
+        raise RuntimeError("Install lark-oapi before starting Feishu long connection") from exc
+
+    event_handler = (
+        lark.EventDispatcherHandler.builder(
+            settings.feishu_encrypt_key or "",
+            settings.feishu_verification_token or "",
+        )
+        .register_p2_im_message_receive_v1(_handle_message_event)
+        .build()
+    )
+    client = lark.ws.Client(
+        app_id=settings.feishu_app_id,
+        app_secret=settings.feishu_app_secret,
+        event_handler=event_handler,
+        log_level=lark.LogLevel.WARNING,
+        domain=_sdk_domain(settings.feishu_base_url),
+    )
+    logger.info("Starting Feishu long connection client")
+    client.start()
+
+
+if __name__ == "__main__":
+    logging.basicConfig(level=logging.INFO)
+    run_long_connection()