feat: implement matchedVia tracking for receipt items and enhance user alias management

backend/src/receipt-import/dto/parsed-receipt-item.dto.ts

@@ -1,5 +1,7 @@
 import type { CategorySuggestion } from '../../ai/ai.service';
 
+export type MatchedVia = 'alias' | 'wordmatch' | 'ai' | 'none';
+
 export interface ParsedReceiptItem {
   rawName: string;
   quantity: number;
@@ -15,4 +17,6 @@ export interface ParsedReceiptItem {
   suggestedProductName?: string;
   // AI-kategorisuggestion för ej matchade varor (premium)
   categorySuggestion?: CategorySuggestion;
+  // matchkälla för UI-visning
+  matchedVia?: MatchedVia;
 }

backend/src/receipt-import/receipt-import.service.spec.ts

@@ -257,4 +257,41 @@ describe('ReceiptImportService test matrix', () => {
       expect(result[0].unit).toBe('st');
     });
   });
+
+  describe('matchedVia', () => {
+    it('sätter matchedVia: alias vid aliasträff', async () => {
+      prismaMock.receiptAlias.findMany.mockResolvedValue([
+        {
+          receiptName: 'snickers',
+          productId: 222,
+          product: { id: 222, name: 'Snickers', canonicalName: 'Snickers', categoryId: null, categoryRef: null },
+        },
+      ]);
+      prismaMock.product.findMany.mockResolvedValue([]);
+
+      const result = await (service as any).matchProducts([{ rawName: 'SNICKERS' }], 10);
+
+      expect(result[0].matchedVia).toBe('alias');
+    });
+
+    it('sätter matchedVia: wordmatch vid ordbaserad matchning', async () => {
+      prismaMock.receiptAlias.findMany.mockResolvedValue([]);
+      prismaMock.product.findMany.mockResolvedValue([
+        { id: 300, name: 'Mjolk', canonicalName: 'Mjolk', categoryId: null, categoryRef: null },
+      ]);
+
+      const result = await (service as any).matchProducts([{ rawName: 'MJOLK 1L' }], 10);
+
+      expect(result[0].matchedVia).toBe('wordmatch');
+    });
+
+    it('sätter matchedVia: none när ingen matchning finns', async () => {
+      prismaMock.receiptAlias.findMany.mockResolvedValue([]);
+      prismaMock.product.findMany.mockResolvedValue([]);
+
+      const result = await (service as any).matchProducts([{ rawName: 'XYZXYZ' }], 10);
+
+      expect(result[0].matchedVia).toBe('none');
+    });
+  });
 });

backend/src/receipt-import/receipt-import.service.ts

@@ -309,6 +309,7 @@ export class ReceiptImportService {
           matchedProductId: alias.product.id,
           matchedProductName: alias.product.canonicalName ?? alias.product.name,
           unit: mappedUnit ?? item.unit,
+          matchedVia: 'alias' as const,
           ...(cat ? { categorySuggestion: { categoryId: cat.id, categoryName: cat.name, path: cat.name, confidence: 'high' as const, usedFallback: false } } : {}),
         };
       }
@@ -316,7 +317,7 @@ export class ReceiptImportService {
       // 2. Ordbaserad matchning (förslag, kräver bekräftelse)
       const suggestion = this.findWordMatch(raw, products);
       if (!suggestion) {
-        return { ...item };
+        return { ...item, matchedVia: 'none' as const };
       }
 
       // Kontrollera om det finns en enhetsmappning för produkten och användaren
@@ -333,6 +334,7 @@ export class ReceiptImportService {
         suggestedProductId: suggestion.id,
         suggestedProductName: suggestion.canonicalName ?? suggestion.name,
         unit: preferredUnit,
+        matchedVia: 'wordmatch' as const,
         ...(cat ? { categorySuggestion: { categoryId: cat.id, categoryName: cat.name, path: cat.name, confidence: 'medium' as const, usedFallback: false } } : {}),
       };
     });
@@ -547,7 +549,7 @@ export class ReceiptImportService {
 
         enriched.push(
           finalSuggestion
-            ? { ...item, categorySuggestion: finalSuggestion }
+            ? { ...item, categorySuggestion: finalSuggestion, matchedVia: item.matchedVia ?? (finalSuggestion ? 'ai' as const : 'none' as const) }
             : item,
         );
       } catch (err) {