client: project config and bootstrap

Add Vite + React + TypeScript setup, package.json (react-router-dom,
socket.io-client), global CSS, app entry point and environment
config.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "contrabbandieri-client",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc --noEmit && vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "react": "^19.1.0",
+    "react-dom": "^19.1.0",
+    "react-router-dom": "^7.6.0",
+    "socket.io-client": "^4.8.1"
+  },
+  "devDependencies": {
+    "@types/react": "^19.1.0",
+    "@types/react-dom": "^19.1.0",
+    "@vitejs/plugin-react": "^4.4.0",
+    "typescript": "^5.8.3",
+    "vite": "^6.3.5"
+  }
+}