Fix SPA and migrate server to TS

deployment/frontend/server.ts

@@ -0,0 +1,28 @@
+import express from 'express';
+import { createProxyMiddleware } from 'http-proxy-middleware';
+import { resolve } from 'path';
+
+const app = express();
+const port = process.env.PORT || 3000;
+const backendHost = process.env.BACKEND_HOST || "http://localhost:8300";
+const filePath = process.env.STATIC_FILE_PATH || ".";
+
+// API proxy middleware
+app.use('/api', createProxyMiddleware({
+    target: backendHost,
+    changeOrigin: true,
+    pathRewrite: { '^/api': '' },
+    ws: true
+}));
+
+// Serve static files
+app.use(express.static(resolve(filePath)));
+
+// SPA routing - catch all handler for client-side routing
+app.get('*', (_req, res) => {
+    res.sendFile(resolve(filePath, 'index.html'));
+});
+
+app.listen(port, () => {
+    console.log(`Server launched on http://localhost:${port}`);
+});