feat: 添加请求验证错误详细日志

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/main.py

@@ -2,10 +2,11 @@
 import logging
 from contextlib import asynccontextmanager
 
-from fastapi import FastAPI
+from fastapi import FastAPI, Request
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse
 from fastapi.staticfiles import StaticFiles
+from fastapi.exceptions import RequestValidationError
 import json
 import os
 
@@ -131,6 +132,20 @@ os.makedirs(upload_path, exist_ok=True)
 app.mount("/static/uploads", StaticFiles(directory=upload_path), name="uploads")
 
 
+# 请求验证错误处理 (422)
+@app.exception_handler(RequestValidationError)
+async def validation_exception_handler(request: Request, exc: RequestValidationError):
+    """处理请求验证错误，记录详细日志"""
+    logger.error(f"请求验证错误 [{request.method} {request.url.path}]: {exc.errors()}")
+    return JSONResponse(
+        status_code=422,
+        content={
+            "detail": exc.errors(),
+            "body": exc.body if hasattr(exc, 'body') else None,
+        },
+    )
+
+
 # 全局异常处理
 @app.exception_handler(Exception)
 async def global_exception_handler(request, exc):