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/receipt-import/receipt-import.service.ts

@@ -7,6 +7,8 @@ import {
 import * as pdfParse from 'pdf-parse';
 import { PrismaService } from '../prisma/prisma.service';
 import { ParsedReceiptItem } from './dto/parsed-receipt-item.dto';
+import { AiService } from '../ai/ai.service';
+import { CategoriesService } from '../categories/categories.service';
 
 const MISTRAL_API_URL = 'https://api.mistral.ai/v1/chat/completions';
 
@@ -36,9 +38,13 @@ ${text}`;
 export class ReceiptImportService {
   private readonly logger = new Logger(ReceiptImportService.name);
 
-  constructor(private readonly prisma: PrismaService) {}
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly aiService: AiService,
+    private readonly categoriesService: CategoriesService,
+  ) {}
 
-  async parseReceipt(file: Express.Multer.File): Promise<ParsedReceiptItem[]> {
+  async parseReceipt(file: Express.Multer.File, isPremium = false): Promise<ParsedReceiptItem[]> {
     const apiKey = process.env.MISTRAL_API_KEY;
     if (!apiKey) {
       throw new ServiceUnavailableException(
@@ -51,7 +57,12 @@ export class ReceiptImportService {
       ? await this.parseReceiptFromPdf(file.buffer, apiKey)
       : await this.parseReceiptFromImage(file.buffer, file.mimetype, apiKey);
 
-    return this.matchProducts(rawItems);
+    const matched = await this.matchProducts(rawItems);
+
+    if (isPremium) {
+      return this.enrichWithAiCategories(matched);
+    }
+    return matched;
   }
 
   private async parseReceiptFromImage(
@@ -221,4 +232,29 @@ export class ReceiptImportService {
       );
     });
   }
+
+  private async enrichWithAiCategories(items: ParsedReceiptItem[]): Promise<ParsedReceiptItem[]> {
+    const unmatched = items.filter((i) => !i.matchedProductId && !i.suggestedProductId && i.rawName);
+    if (unmatched.length === 0) return items;
+
+    let categories: Awaited<ReturnType<CategoriesService['findFlattened']>>;
+    try {
+      categories = await this.categoriesService.findFlattened();
+    } catch {
+      return items; // Om kategoritjänsten är otillgänglig, returnera utan AI-förslag
+    }
+
+    const enriched = new Map<string, ParsedReceiptItem>();
+    for (const item of unmatched) {
+      try {
+        const suggestion = await this.aiService.suggestCategory(item.rawName, categories);
+        enriched.set(item.rawName, { ...item, categorySuggestion: suggestion });
+      } catch {
+        // Om AI-anrop misslyckas för enskild vara — hoppa över utan att kasta
+        enriched.set(item.rawName, item);
+      }
+    }
+
+    return items.map((item) => enriched.get(item.rawName) ?? item);
+  }
 }