- Add guest checkout flow: customers can now complete orders without creating an account
- New /checkout page with login or guest options
- Guest form collects: full name, email, phone, address
- Orders track guest info via guestName and guestPhone fields
- Update cart message to reflect guest option
- Add "Admin login" link to customer login page for clear navigation
- Update checkout API to accept and store guest information
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
