feat: Major UI enhancement with BlackRoad brand system

- Add stunning landing page with hero, features, and CTA sections
- Update login/signup pages with dark theme and brand gradients
- Enhance Sidebar with improved navigation and brand colors
- Update AppHeader with search bar, notifications, and user menu
- Add reusable UI components (Button, Card, Input, Badge)
- Add API health and status endpoints
- Apply official BlackRoad brand colors (#FF1D6C hot pink, #F5A623 amber, #2979FF electric blue, #9C27B0 violet)

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

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

components/ui/index.ts

@@ -0,0 +1,4 @@
+export { default as Button } from './Button';
+export { default as Card, CardHeader, CardTitle, CardDescription, CardContent, CardFooter } from './Card';
+export { default as Input } from './Input';
+export { default as Badge } from './Badge';