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/components/auth/PasswordResetForm.jsx

@@ -104,7 +104,7 @@ const PasswordResetForm = () => {
   }
 
   return (
-    <div className='relative overflow-hidden bg-gray-100 flex items-center justify-center py-12 px-4 sm:px-6 lg:px-8'>
+    <div className='classic-page-fill relative overflow-hidden bg-gray-100 flex items-center justify-center py-12 px-4 sm:px-6 lg:px-8'>
       {/* 背景模糊晕染球 */}
       <div
         className='blur-ball blur-ball-indigo'