feat(chess): scaffold Vite + React app (P3.9)

packages/chess/src/app/App.tsx

@@ -0,0 +1,46 @@
+import { Routes, Route } from 'react-router-dom'
+
+export function App() {
+  return (
+    <div data-testid="app-root">
+      <Routes>
+        <Route path="/" element={<Home />} />
+        <Route path="/game" element={<Game />} />
+        <Route path="/rules" element={<Rules />} />
+        <Route path="/save" element={<Save />} />
+      </Routes>
+    </div>
+  )
+}
+
+function Home() {
+  return (
+    <main data-testid="page-home">
+      <h1>Home</h1>
+    </main>
+  )
+}
+
+function Game() {
+  return (
+    <main data-testid="page-game">
+      <h1>Game</h1>
+    </main>
+  )
+}
+
+function Rules() {
+  return (
+    <main data-testid="page-rules">
+      <h1>Rules</h1>
+    </main>
+  )
+}
+
+function Save() {
+  return (
+    <main data-testid="page-save">
+      <h1>Save</h1>
+    </main>
+  )
+}

packages/chess/src/app/index.css

@@ -0,0 +1 @@
+@import "tailwindcss";

packages/chess/src/app/main.tsx

@@ -0,0 +1,17 @@
+import { StrictMode } from 'react'
+import { createRoot } from 'react-dom/client'
+import { BrowserRouter } from 'react-router-dom'
+import './index.css'
+import { App } from './App'
+
+const container = document.getElementById('root')
+if (!container) throw new Error('Failed to find the root element')
+
+const root = createRoot(container)
+root.render(
+  <StrictMode>
+    <BrowserRouter>
+      <App />
+    </BrowserRouter>
+  </StrictMode>
+)