feat(docs): 自定义Swagger UI使用CDN加载静态资源

禁用FastAPI默认的/docs和/redoc路由，添加自定义Swagger UI端点
从CDN加载静态资源以解决本地网络问题

app/main.py

 from fastapi import FastAPI
+from fastapi.openapi.docs import get_swagger_ui_html
 from fastapi.middleware.cors import CORSMiddleware
 from app.api.v1.router import api_router
 from app.core.config import settings
@@ -25,7 +26,9 @@ app = FastAPI(
         {"name": "管理员", "description": "管理员功能（敏感词、分类等）"},
         {"name": "对话", "description": "对话与敏感词审计接口"},
     ],
-    openapi_url=f"{settings.API_V1_STR}/openapi.json"
+    openapi_url=f"{settings.API_V1_STR}/openapi.json",
+    docs_url=None,  # 禁用默认的/docs
+    redoc_url=None  # 禁用默认的/redoc
 )
 
 # 配置CORS
@@ -37,6 +40,16 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
+# 自定义Swagger UI，从CDN加载静态资源，解决本地网络问题
+@app.get("/docs", include_in_schema=False)
+async def custom_swagger_ui_html():
+    return get_swagger_ui_html(
+        openapi_url=app.openapi_url,
+        title=app.title + " - Swagger UI",
+        swagger_js_url="https://cdnjs.cloudflare.com/ajax/libs/swagger-ui/5.9.0/swagger-ui-bundle.js",
+        swagger_css_url="https://cdnjs.cloudflare.com/ajax/libs/swagger-ui/5.9.0/swagger-ui.css",
+    )
+
 # 注册API路由
 app.include_router(api_router, prefix=settings.API_V1_STR)