- Storage Integration:
* Remove Firebase Storage dependency and useFirebaseStorage composable
* Implement direct MinIO uploads via POST /storage/upload with multipart/form-data
* Upload canvas JSON, preview PNG, and production PNG as separate objects
* Store public URLs and metadata in design records
- Authentication & Registration:
* Add email/password registration page with validation
* Integrate backend user session via /auth/login endpoint
* Store backendUser.id as ownerId in design records
* Auto-sync backend session on Firebase auth state changes
- User Account Pages:
* Create profile page showing user details and backend session info
* Create orders page with transaction history filtered by customerEmail
* Add server proxy /api/orders to forward GET /transactions queries
- Navigation Improvements:
* Replace inline auth buttons with avatar dropdown menu
* Add Profile, Orders, and Logout options to dropdown
* Implement outside-click and route-change handlers for dropdown
* Display user initials in avatar badge
- API Updates:
* Update transactions endpoint to accept amount as string
* Format amount with .toFixed(2) in checkout success flow
* Query orders by customerEmail instead of ownerId for consistency
