Refactor: Rename DocumentOperator to DocumentService

Updated project and solution files to rename and restructure
`DocumentOperator` to `DocumentService`. Modified project
references in `DocumentService.API.csproj`, `DocumentService.Application.csproj`,
and `DocumentService.Infrastructure.csproj` to reflect the new
naming convention. Updated `DocumentService.sln` to remove
old project references, add new ones, and adjust configuration
and nested project mappings accordingly. This change aligns
the project structure with the new naming convention.

DocumentService.API/Controllers/SwissQrCodeController.cs

@@ -0,0 +1,113 @@
+using DocumentService.Application.Common.DTOs;
+using DocumentService.Application.SwissQrCode.Queries;
+using DocumentService.Domain.Common.Exceptions;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DocumentService.API.Controllers;
+
+/// <summary>
+/// Swiss QR Code extraction operations
+/// </summary>
+[ApiController]
+[Route("api/pdf/qr-code")]
+[Produces("application/json")]
+public class SwissQrCodeController(IMediator Mediator) : ControllerBase
+{
+    /// <summary>
+    /// Extracts Swiss QR Code from the last page of a PDF document (multipart/form-data)
+    /// </summary>
+    /// <param name="file">PDF file containing Swiss QR Code</param>
+    /// <param name="raw">If true, returns raw QR text lines instead of parsed Bill object</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Swiss QR Code data (IBAN, amount, creditor, debtor, reference, etc.)</returns>
+    /// <response code="200">Swiss QR Code extracted successfully</response>
+    /// <response code="400">Invalid PDF or file format</response>
+    /// <response code="404">No Swiss QR Code found on the last page</response>
+    /// <response code="500">Internal server error during extraction</response>
+    [HttpPost("extract-swiss")]
+    [Consumes("multipart/form-data")]
+    [ProducesResponseType(typeof(SwissQrCodeExtractionResult), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
+    public async Task<IActionResult> ExtractFromFile(
+        IFormFile file,
+        [FromQuery] bool raw = false,
+        CancellationToken cancellationToken = default)
+    {
+        if (file.Length == 0)
+            return BadRequest(new ProblemDetails
+            {
+                Title = "Invalid file",
+                Detail = "File is required and cannot be empty",
+                Status = StatusCodes.Status400BadRequest
+            });
+
+        // Use IFormFile stream directly (no intermediate byte[] conversion)
+        using var pdfStream = file.OpenReadStream();
+
+        // Direct pass-through to MediatR
+        var query = new ExtractSwissQrCodeQuery 
+        { 
+            PdfStream = pdfStream
+        };
+        var result = await Mediator.Send(query, cancellationToken);
+
+        return Ok(raw ? result.RawLines : result.Bill);
+    }
+
+    /// <summary>
+    /// Extracts Swiss QR Code from the last page of a PDF document (Base64 JSON)
+    /// </summary>
+    /// <param name="request">Request containing Base64-encoded PDF</param>
+    /// <param name="raw">If true, returns raw QR text lines instead of parsed Bill object</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Swiss QR Code data (IBAN, amount, creditor, debtor, reference, etc.)</returns>
+    /// <response code="200">Swiss QR Code extracted successfully</response>
+    /// <response code="400">Invalid PDF or Base64 format</response>
+    /// <response code="404">No Swiss QR Code found on the last page</response>
+    /// <response code="500">Internal server error during extraction</response>
+    [HttpPost("extract-swiss")]
+    [Consumes("application/json")]
+    [ProducesResponseType(typeof(SwissQrCodeExtractionResult), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status404NotFound)]
+    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status500InternalServerError)]
+    public async Task<IActionResult> ExtractFromBase64(
+        [FromBody] ExtractSwissQrCodeBase64Request request,
+        [FromQuery] bool raw = false,
+        CancellationToken cancellationToken = default)
+    {
+        // Convert Base64 to stream (wrap in try-catch to throw BadRequestException)
+        byte[] pdfBytes;
+        try
+        {
+            pdfBytes = Convert.FromBase64String(request.Base64Pdf);
+        }
+        catch (FormatException ex)
+        {
+            throw new BadRequestException("Invalid Base64 format: " + ex.Message);
+        }
+        
+        using var pdfStream = new MemoryStream(pdfBytes);
+        
+        // Direct pass-through to MediatR
+        var query = new ExtractSwissQrCodeQuery { PdfStream = pdfStream };
+        var result = await Mediator.Send(query, cancellationToken);
+
+        return Ok(raw ? result.RawLines : result.Bill);
+    }
+}
+
+/// <summary>
+/// Request DTO for Base64-encoded Swiss QR Code extraction
+/// </summary>
+public record ExtractSwissQrCodeBase64Request
+{
+    /// <summary>
+    /// PDF document encoded as Base64 string
+    /// </summary>
+    /// <example>JVBERi0xLjQKJeLjz9MKMSAwIG9iago8PC9UeXBlL0NhdGFsb2c...</example>
+    public required string Base64Pdf { get; init; }
+}