feat: Mobile optimization and UI improvements

- Add mobile hamburger menu in TopBar with slide-in panel
- Optimize all components for mobile (responsive fonts, spacing, touch targets)
- Add proper viewport meta tags and safe area padding
- Fix /jackpot/next API to return active cycles regardless of scheduled time
- Remove BTC display from jackpot pot (show sats only)
- Add setup/ folder to .gitignore
- Improve mobile UX: 16px inputs (no iOS zoom), 44px touch targets
- Add active states for touch feedback on buttons

front_end/src/app/layout.tsx

@@ -1,4 +1,4 @@
-import type { Metadata } from 'next';
+import type { Metadata, Viewport } from 'next';
 import { Inter } from 'next/font/google';
 import './globals.css';
 import { Providers } from './providers';
@@ -7,9 +7,25 @@ import { Footer } from '@/components/Footer';
 
 const inter = Inter({ subsets: ['latin'] });
 
+export const viewport: Viewport = {
+  width: 'device-width',
+  initialScale: 1,
+  maximumScale: 5,
+  userScalable: true,
+  themeColor: '#0b0b0b',
+};
+
 export const metadata: Metadata = {
   title: 'Lightning Lottery - Win Bitcoin',
   description: 'Bitcoin Lightning Network powered lottery with instant payouts',
+  appleWebApp: {
+    capable: true,
+    statusBarStyle: 'black-translucent',
+    title: 'Lightning Lotto',
+  },
+  formatDetection: {
+    telephone: false,
+  },
 };
 
 export default function RootLayout({