feat(web): support classic Rsbuild dev and build

- migrate the classic frontend from Vite to Rsbuild with JSX, Semi UI, proxy, and production build config.
- update make dev-web to run both default and classic frontends for local theme switching.
- fix classic public page height, footer, CORS proxy, error handling, and constant export warnings.
- update Dockerfile and release workflow to install from the web workspace root with the shared lockfile.

web/classic/src/helpers/utils.jsx

@@ -123,7 +123,7 @@ export function showError(error) {
   console.error(error);
   if (error.message) {
     if (error.name === 'AxiosError') {
-      switch (error.response.status) {
+      switch (error.response?.status) {
         case 401:
           // 清除用户状态
           localStorage.removeItem('user');