- Add DesignApproval and DesignApprovalMessage models for design review workflow
- Add design approval admin interface (list, detail, chat, approve/reject)
- Add per-image dimension tracking to OrderItem
- Add design submission API endpoint
- Add AdminDesignEditor for admin-side design modifications
- Add DesignApprovalChat component for customer-admin communication
- Update design specification generation with image dimension details
- Add design persistence across login with next parameter redirect
- Add font properties UI with font size and color display
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>