Round 3 fixes: cancelled polling, aggregator invalid_count, filter state, scheduler atomicity, HTTP exception handler, tests

app/api/main.py

@@ -3,9 +3,10 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from app.api.lifespan import lifespan
 from app.api.routes import api_router
-from app.api.errors import proxy_pool_exception_handler, pydantic_validation_handler, general_exception_handler
+from app.api.errors import proxy_pool_exception_handler, http_exception_handler, pydantic_validation_handler, general_exception_handler
 from app.core.exceptions import ProxyPoolException
 from pydantic import ValidationError
+from starlette.exceptions import HTTPException as StarletteHTTPException
 from app.core.config import settings as app_settings
 
 # 导入并注册所有插件（显式注册模式）
@@ -30,6 +31,7 @@ def create_app() -> FastAPI:
 
     # 异常处理
     app.add_exception_handler(ProxyPoolException, proxy_pool_exception_handler)
+    app.add_exception_handler(StarletteHTTPException, http_exception_handler)
     app.add_exception_handler(ValidationError, pydantic_validation_handler)
     app.add_exception_handler(Exception, general_exception_handler)