feat: add frontend source (fix submodule), compact node design

- Remove nested .git from Vite scaffold
- Horizontal node layout: icon left, label+IP right, reduced height

frontend/vite.config.ts

@@ -0,0 +1,22 @@
+import path from 'path'
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+import tailwindcss from '@tailwindcss/vite'
+
+export default defineConfig({
+  plugins: [react(), tailwindcss()],
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './src'),
+    },
+  },
+  server: {
+    proxy: {
+      '/api': 'http://localhost:8000',
+      '/ws': {
+        target: 'ws://localhost:8000',
+        ws: true,
+      },
+    },
+  },
+})