- Add customer password change page at /account/change-password
- Add admin password change page at /admin/change-password
- Create AdminUser database table for storing admin credentials
- Admin login now checks database first, falls back to env vars
- Update admin auth to support bcrypt password hashing
- Add change password links to customer account and admin nav
- Fix customer login logs back link (was pointing to non-existent /admin)
- Add success/error message handling for password changes
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
