Initial commit: Set up Garmin Health Lab project structure

- Initialize monorepo with root workspace configuration
- Set up Express.js backend with TypeScript
- Set up React 18 frontend with TypeScript
- Create database schema with SQLite
- Implement project architecture and documentation
- Add development and deployment guidelines

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

client/src/index.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>
+);