fix(upload): 修复上传文件问题

handlers/message.py

@@ -1,10 +1,11 @@
 """消息发送处理器：JSON 解析、参数校验、QQ API 超时与重试。"""
 
 import asyncio
+from pathlib import Path
 
 from aiohttp import web
 
-from ..config import QQ_API_MAX_RETRIES, QQ_API_TIMEOUT
+from ..config import QQ_API_MAX_RETRIES, QQ_API_TIMEOUT, UPLOAD_DIR
 from ..response import error, ok
 
 VALID_MSG_TYPES = {"text", "image", "file", "video"}
@@ -80,6 +81,11 @@ async def webhook_handler(request: web.Request) -> web.Response:
     msg = data.get("msg", "")
     url = data.get("url", "")
 
+    # 如果 url 是本地已上传的文件（相对路径），补全为绝对路径
+    file_path = Path(url)
+    if not file_path.is_absolute() and (UPLOAD_DIR / url).exists():
+        url = str((UPLOAD_DIR / url).resolve())
+
     # 获取 ncatbot API 实例
     api = request.app["qq_api"]