Initial scaffold: FastAPI backend + React frontend + Docker Compose

- Backend: FastAPI with SQLite, clip CRUD, health check
- Frontend: React + Vite + TypeScript + Tailwind, dark theme
- Components: Generator, Gallery, Player
- Docker: Compose setup for backend + frontend
- Architecture docs in Palace KB

frontend/src/main.tsx

@@ -0,0 +1,10 @@
+import React from 'react'
+import ReactDOM from 'react-dom/client'
+import App from './App'
+import './index.css'
+
+ReactDOM.createRoot(document.getElementById('root')!).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>,
+)