Redesign login as landing page, remove self-registration, add nav+placeholders
- LoginPage: centred landing layout with logo placeholder box and business
name headline (BUSINESS_NAME constant); registration link removed
- useAuth: post-login redirect goes to / (dashboard) directly
- Nav: Home | Apps | Settings | Logout (consistent on all protected pages)
- AppsPage, SettingsPage: white placeholder pages with headline
- App.tsx: /apps and /settings private routes; removed /register,
/register-success, /login-success; catch-all → /
- Deleted: RegisterPage, RegisterSuccessPage, LoginSuccessPage
- Backend /api/auth/register kept for future admin-side user creation
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
