Initial commit: Expo app with Better Auth integration

- Complete Expo React Native app setup with TypeScript
- Better Auth authentication system integration
- Secure storage implementation for session tokens
- Authentication flow with login/logout functionality
- API client configuration for backend communication
- Responsive UI components with themed styling
- Expo Router navigation setup
- Development configuration and scripts

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

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

components/themed-view.tsx

@@ -0,0 +1,14 @@
+import { View, type ViewProps } from 'react-native';
+
+import { useThemeColor } from '@/hooks/use-theme-color';
+
+export type ThemedViewProps = ViewProps & {
+  lightColor?: string;
+  darkColor?: string;
+};
+
+export function ThemedView({ style, lightColor, darkColor, ...otherProps }: ThemedViewProps) {
+  const backgroundColor = useThemeColor({ light: lightColor, dark: darkColor }, 'background');
+
+  return <View style={[{ backgroundColor }, style]} {...otherProps} />;
+}