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/render.jsx

@@ -94,7 +94,6 @@ import {
   SiGitlab,
   SiGoogle,
   SiKeycloak,
-  SiLinkedin,
   SiNextcloud,
   SiNotion,
   SiOkta,
@@ -106,6 +105,7 @@ import {
   SiWechat,
   SiX,
 } from 'react-icons/si';
+import { FaLinkedin } from 'react-icons/fa';
 
 // 获取侧边栏Lucide图标组件
 export function getLucideIcon(key, selected = false) {
@@ -509,7 +509,7 @@ const oauthProviderIconMap = {
   google: SiGoogle,
   discord: SiDiscord,
   facebook: SiFacebook,
-  linkedin: SiLinkedin,
+  linkedin: FaLinkedin,
   x: SiX,
   twitter: SiX,
   slack: SiSlack,