MAJOR UPPDATE: "First Ai"

feat: add AI categorization for products and enhance user management

- Integrated AI service for category suggestions in receipt import and product management.
- Added premium subscription feature for users with corresponding API endpoints.
- Implemented admin interface for managing pending product suggestions.
- Enhanced user management to include premium status and corresponding UI updates.
- Updated database schema to support new fields for premium status and product status.

backend/prisma/schema.prisma

@@ -15,6 +15,7 @@ model User {
   lastName     String?
   passwordHash String
   role         String       @default("user")
+  isPremium    Boolean      @default(false)
   createdAt    DateTime     @default(now())
   updatedAt    DateTime     @updatedAt
 
@@ -33,6 +34,7 @@ model Product {
   brand          String?
   canonicalName  String?
   isActive       Boolean         @default(true)
+  status         String           @default("active")
   deletedAt      DateTime?
   createdAt      DateTime        @default(now())
   updatedAt      DateTime        @updatedAt