Add Phase 2 & 3: Web frontend with authentication and tracking features

- Initialize Next.js 14 web application with Material UI and TypeScript
- Implement authentication (login/register) with device fingerprint
- Create mobile-first responsive layout with app shell pattern
- Add tracking pages for feeding, sleep, and diaper changes
- Implement activity history with filtering
- Configure backend CORS for web frontend (port 3030)
- Update backend port to 3020, frontend to 3030
- Fix API response handling for auth endpoints

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

maternal-web/hooks/useMediaQuery.ts

@@ -0,0 +1,19 @@
+import { useState, useEffect } from 'react';
+
+export const useMediaQuery = (query: string): boolean => {
+  const [matches, setMatches] = useState(false);
+
+  useEffect(() => {
+    const media = window.matchMedia(query);
+    if (media.matches !== matches) {
+      setMatches(media.matches);
+    }
+
+    const listener = () => setMatches(media.matches);
+    media.addEventListener('change', listener);
+
+    return () => media.removeEventListener('change', listener);
+  }, [matches, query]);
+
+  return matches;
+};