feat: Expo scaffold + auth screens + core screens (#39-#46, #48)

components/index.ts

@@ -0,0 +1,8 @@
+export { AppButton } from './AppButton';
+export { AppInput } from './AppInput';
+export { AppCard } from './AppCard';
+export { StatusBadge } from './StatusBadge';
+export { LoadingSpinner } from './LoadingSpinner';
+export { EmptyState } from './EmptyState';
+export { Avatar } from './Avatar';
+export { ConfirmModal } from './ConfirmModal';