add beta notice

src/App.tsx

@@ -2,7 +2,7 @@ import { createTheme, CssBaseline, GlobalStyles, styled, ThemeProvider, useMedia
 import { grey } from "@mui/material/colors";
 import { ThemeOptions } from "@mui/material/styles/createTheme";
 import i18next from "i18next";
-import { enqueueSnackbar, MaterialDesignContent, SnackbarProvider } from "notistack";
+import { enqueueSnackbar, MaterialDesignContent, SnackbarProvider, useSnackbar } from "notistack";
 import { Suspense, useEffect, useMemo } from "react";
 import { useTranslation } from "react-i18next";
 import { Outlet } from "react-router-dom";
@@ -300,6 +300,15 @@ const AppContent = () => {
   const title = useAppSelector((state) => state.siteConfig.basic.config.title);
   const theme = useTheme();
   const isMobile = useMediaQuery(theme.breakpoints.down("sm"));
+  const { enqueueSnackbar } = useSnackbar();
+
+  useEffect(() => {
+    // 显示测试网站提示
+    enqueueSnackbar("请注意，本网站是测试网站", {
+      variant: "warning",
+      autoHideDuration: 5000,
+    });
+  }, [enqueueSnackbar]);
   const scrollBar = {
     "&::-webkit-scrollbar-button": {
       width: 0,