1、后台系统设置settings页面增加一个开启关闭网站的按钮

2、如果网站关闭，前台页面所有请求暂时跳转单独的页如果网站关闭，前台页面所有请求暂时跳转单独的页面，页面内容 系统正在升级相关信息
3、要提供一个开发人员可以查看真实网站内容的入口

video-gen-api/app/main.py

@@ -16,6 +16,7 @@ from app.middleware.logging import RequestLoggingMiddleware
 from app.middleware.anti_crawler import AntiCrawlerMiddleware
 from app.middleware.rate_limit import RateLimitMiddleware
 from app.middleware.request_encrypt import RequestEncryptMiddleware
+from app.middleware.site_status import SiteStatusMiddleware
 from app.services.log_config import decrypt_data
 
 logging.basicConfig(level=logging.INFO if settings.DEBUG else logging.WARNING)
@@ -29,6 +30,7 @@ async def lifespan(app: FastAPI):
     os.makedirs(settings.UPLOAD_LOCAL_PATH, exist_ok=True)
     await init_database()
     await init_redis()
+    await _ensure_site_configs()
     # await _seed_data()
 
     # Start task queue (handles both video and image generation)
@@ -513,6 +515,40 @@ async def _seed_data():
         await db.commit()
 
 
+async def _ensure_site_configs() -> None:
+    """确保网站开关相关配置项存在（不存在则自动创建）。"""
+    import secrets
+    from app.models.base import async_session
+    from app.models.system_config import SystemConfig
+    from app.utils.id_gen import generate_id
+    from sqlalchemy import select
+
+    async with async_session() as db:
+        # site_enabled
+        existing = await db.execute(
+            select(SystemConfig).where(SystemConfig.key == "site_enabled").limit(1)
+        )
+        if not existing.scalar_one_or_none():
+            db.add(SystemConfig(
+                id=generate_id(),
+                key="site_enabled",
+                value="true",
+                description="网站访问开关（true=开启，false=关闭）",
+            ))
+        # site_dev_access_token
+        existing_token = await db.execute(
+            select(SystemConfig).where(SystemConfig.key == "site_dev_access_token").limit(1)
+        )
+        if not existing_token.scalar_one_or_none():
+            db.add(SystemConfig(
+                id=generate_id(),
+                key="site_dev_access_token",
+                value=secrets.token_urlsafe(32),
+                description="开发者访问令牌（网站关闭时用于绕过限制）",
+            ))
+        await db.commit()
+
+
 def create_app() -> FastAPI:
     application = FastAPI(
         title=settings.APP_NAME,
@@ -522,7 +558,8 @@ def create_app() -> FastAPI:
         redoc_url="/internal/api-redoc",
     )
 
-    # Middleware (outermost first)
+    # Middleware (outermost first) — SiteStatus 放最外层，早于其他中间件拦截
+    application.add_middleware(SiteStatusMiddleware)
     application.add_middleware(RequestLoggingMiddleware)
     application.add_middleware(AntiCrawlerMiddleware)
     application.add_middleware(RateLimitMiddleware)