Replace frontend with real working CAD editor source from /data/web-cad-neu (TS, React 18, full ribbon bar, KI, layers, tools)

frontend/vite.config.ts

@@ -0,0 +1,12 @@
+import { defineConfig } from 'vite';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig({
+  plugins: [react()],
+  server: {
+    proxy: {
+      '/api': 'http://localhost:3001',
+      '/ws': { target: 'ws://localhost:3001', ws: true }
+    }
+  }
+});