[backend] fix: 修复异常处理和类型转换问题

backend/main.py

@@ -31,8 +31,8 @@ app.include_router(users_router, prefix="/api/v1")
 app.include_router(projects_router, prefix="/api/v1")
 
 
-@app.exception_handler(StarletteHTTPException)
-async def http_exception_handler(request: Request, exc: StarletteHTTPException):
+@app.exception_handler(HTTPException)
+async def http_exception_handler(request: Request, exc: HTTPException):
     if isinstance(exc.detail, dict):
         return JSONResponse(
             status_code=exc.status_code,
@@ -49,6 +49,19 @@ async def http_exception_handler(request: Request, exc: StarletteHTTPException):
     )
 
 
+@app.exception_handler(StarletteHTTPException)
+async def starlette_http_exception_handler(request: Request, exc: StarletteHTTPException):
+    return JSONResponse(
+        status_code=exc.status_code,
+        content={
+            "success": False,
+            "message": str(exc.detail),
+            "data": None,
+            "error_code": None,
+        },
+    )
+
+
 @app.exception_handler(RequestValidationError)
 async def validation_exception_handler(request: Request, exc: RequestValidationError):
     return JSONResponse(