fix: lint - 114 errors fixed (unused imports, indentation, blank lines)

src/main.py

@@ -191,7 +191,6 @@ async def lifespan(app: FastAPI):
     )
 
     # ExperienceDistiller（经验自动蒸馏）
-    experience_config = config.get("experience", {})
     experience_distiller = ExperienceDistiller(
         store=ExperienceStore(store_path=DATA_ROOT / "experiences.jsonl"),
     )
@@ -252,13 +251,13 @@ app.add_middleware(
 # API 路由注册
 # ---------------------------------------------------------------------------
 
-from src.api.blackboard_routes import router as blackboard_router
-from src.api.checkpoint_routes import router as checkpoint_router
-from src.api.daemon_routes import router as daemon_router
-from src.api.project_routes import router as project_router
-from src.api.sse_routes import router as sse_router
-from src.api.mail_routes import router as mail_router
-from src.api.toolchain_routes import router as toolchain_router
+from src.api.blackboard_routes import router as blackboard_router  # noqa: E402
+from src.api.checkpoint_routes import router as checkpoint_router  # noqa: E402
+from src.api.daemon_routes import router as daemon_router  # noqa: E402
+from src.api.project_routes import router as project_router  # noqa: E402
+from src.api.sse_routes import router as sse_router  # noqa: E402
+from src.api.mail_routes import router as mail_router  # noqa: E402
+from src.api.toolchain_routes import router as toolchain_router  # noqa: E402
 
 app.include_router(blackboard_router)
 app.include_router(checkpoint_router)
@@ -300,16 +299,16 @@ async def list_projects_compat():
 DIST_DIR = Path(__file__).parent / "frontend" / "dist"
 if DIST_DIR.exists():
     # v3.1: 缓存策略 - HTML 不缓存（确保新版本生效），JS/CSS 长缓存（Vite content hash 已处理）
-    import mimetypes
     _static_app = StaticFiles(directory=str(DIST_DIR), html=True)
-    
+
     class CachedStaticFiles:
         """包装 StaticFiles，添加 Cache-Control 头"""
         def __init__(self, app):
             self._app = app
-        
+
         async def __call__(self, scope, receive, send):
             original_send = send
+
             async def patched_send(message):
                 if message.get("type") == "http.response.start":
                     headers = dict(message.get("headers", []))
@@ -321,5 +320,5 @@ if DIST_DIR.exists():
                     message["headers"] = list(headers.items())
                 await original_send(message)
             await self._app(scope, receive, patched_send)
-    
+
     app.mount("/", CachedStaticFiles(_static_app), name="frontend")