refactor: Update Application layer for Codecrete Bill integration

- Change SwissQrCodeExtractionResult to use Bill + RawLines
- Update ISwissQrCodeProcessor to return tuple (Bill, string[])
- Add Codecrete.SwissQRBill.Generator v3.4.0 package reference
- Update ExtractSwissQrCodeQuery handler to use AutoMapper for Bill->DTO mapping
- Remove References property from query (not needed for QR extraction)

DocumentOperator.Application/Common/Interfaces/ISwissQrCodeProcessor.cs

@@ -1,4 +1,4 @@
-using DocumentOperator.Domain.ValueObjects;
+using Codecrete.SwissQRBill.Generator;
 
 namespace DocumentOperator.Application.Common.Interfaces;
 
@@ -9,16 +9,21 @@ namespace DocumentOperator.Application.Common.Interfaces;
 public interface ISwissQrCodeProcessor
 {
     /// <summary>
-    /// Extracts and parses Swiss QR Code from the last page of a PDF document.
+    /// Extracts and parses Swiss QR Code from a PDF document.
+    /// Returns both parsed Bill object and raw QR text lines.
     /// </summary>
     /// <param name="pdfBytes">PDF document as byte array</param>
+    /// <param name="pageNumbers">Optional: Specific page numbers to scan (1-indexed). If null, scans all pages starting with last page.</param>
     /// <param name="cancellationToken">Cancellation token</param>
-    /// <returns>Parsed Swiss QR Code data</returns>
+    /// <returns>Tuple: (Parsed Codecrete Bill, Raw QR lines as string array)</returns>
     /// <exception cref="Domain.Exceptions.SwissQrCodeNotFoundException">
-    /// Thrown when no Swiss QR Code is found on the last page
+    /// Thrown when no Swiss QR Code is found in the specified pages
     /// </exception>
     /// <exception cref="Domain.Exceptions.PdfProcessingException">
     /// Thrown when PDF processing fails
     /// </exception>
-    Task<SwissQrCodeData> ExtractSwissQrCodeAsync(byte[] pdfBytes, CancellationToken cancellationToken = default);
+    Task<(Bill Bill, string[] RawLines)> ExtractSwissQrCodeAsync(
+        byte[] pdfBytes, 
+        int[]? pageNumbers = null, 
+        CancellationToken cancellationToken = default);
 }