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/src/users/users.service.ts

@@ -25,7 +25,7 @@ export class UsersService {
 
   findAll() {
     return this.prisma.user.findMany({
-      select: { id: true, username: true, email: true, firstName: true, lastName: true, role: true, createdAt: true },
+      select: { id: true, username: true, email: true, firstName: true, lastName: true, role: true, isPremium: true, createdAt: true },
       orderBy: { username: 'asc' },
     });
   }
@@ -34,6 +34,10 @@ export class UsersService {
     return this.prisma.user.update({ where: { id }, data: { role } });
   }
 
+  setPremium(id: number, isPremium: boolean) {
+    return this.prisma.user.update({ where: { id }, data: { isPremium } });
+  }
+
   async adminCreate(data: { username: string; email: string; password: string; role?: string }) {
     const existing = await this.prisma.user.findFirst({
       where: { OR: [{ username: data.username }, { email: data.email }] },