Initial commit: Phase 1 scaffolding complete

- Root package.json with concurrently for dev server
- Client: Vite + React 18 with design tokens and proxy config
- Server: Express with CORS, multer (20MB), Sharp resize
- Upload endpoint with preview generation
- Dockerfile (multi-stage) and docker-compose.yml
- Canvas deferred to Phase 8 (export functionality)

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

client/src/main.jsx

@@ -0,0 +1,31 @@
+import { StrictMode, useEffect, useState } from 'react'
+import { createRoot } from 'react-dom/client'
+import './index.css'
+
+function AppWithHealth() {
+  const [serverStatus, setServerStatus] = useState('Checking...');
+
+  useEffect(() => {
+    fetch('/api/health')
+      .then(res => res.ok ? setServerStatus('Connected ✓') : setServerStatus('Error'))
+      .catch(() => setServerStatus('Offline'));
+  }, []);
+
+  return (
+    <div style={{ padding: '2rem', textAlign: 'center' }}>
+      <h1>Apparel Designer</h1>
+      <p style={{ color: 'var(--text-secondary)' }}>
+        T-shirt customization editor
+      </p>
+      <div style={{ marginTop: '2rem', padding: '1rem', background: 'var(--bg-secondary)', borderRadius: 'var(--radius-md)' }}>
+        <p>Server Status: <code id="server-status">{serverStatus}</code></p>
+      </div>
+    </div>
+  );
+}
+
+createRoot(document.getElementById('root')).render(
+  <StrictMode>
+    <AppWithHealth />
+  </StrictMode>,
+)