chore(import): improve error handling and add flyer integration

- Replace BadRequestException with UnauthorizedException for authentication failures in flyer-import and flyer-selection controllers
- Add bulk selection endpoint in FlyerSelectionController for creating multiple selections in one request
- Update FlyerSelectionModule to include new FlyerSelectionMatcherService and FlyerSelectionSyncController
- Extend FlyerSelectionService with createMany method for bulk operations
- Add new DTOs for bulk selection and receipt matching functionality
- Update ReceiptImportService to accept FlyerSelectionService dependency and track successful rows
- Extend SaveReceiptResponse with flyerAutoSync field for receipt-to-flyer matching results
- Add new API paths for flyer import and selection endpoints
- Update Flutter UI to include Flyer import tab and adjust tab controller length
- Add new domain models and repository methods for flyer import functionality
- Update test files to include new FlyerSelectionService dependency
- Modify .kilo plan documentation to reflect current system architecture

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

@@ -67,12 +67,13 @@ describe('ReceiptImportService.saveReceipt', () => {
       $transaction: jest.fn().mockImplementation(async (cb: (tx: typeof txMock) => Promise<void>) => cb(txMock)),
     };
 
-    service = new ReceiptImportService(
-      prismaMock as any,
-      {} as any, // aiService – används ej i saveReceipt
-      {} as any, // categoriesService – används ej i saveReceipt
-    );
-  });
+    service = new ReceiptImportService(
+      prismaMock as any,
+      {} as any, // aiService – används ej i saveReceipt
+      {} as any, // categoriesService – används ej i saveReceipt
+      { commitReceiptMatches: jest.fn().mockResolvedValue({ boughtCount: 0, ambiguousCount: 0, unmatchedCount: 0 }) } as any,
+    );
+  });
 
   // ── 1. Skapar ny inventariepost ─────────────────────────────────────────────
   it('skapar ny inventariepost när produkten finns och inte finns i inventariet', async () => {