test: Update integration tests for Controller-based API

Integration test updates:

  - PdfValidationControllerTests.cs (new)

    - Test /api/pdf/validation/validate endpoint

    - Test BOTH multipart/form-data AND Base64 JSON

  - ExtractSwissQrCodeEndpointTests.cs (updated)

    - Update endpoint path to /api/swissqrcode/extract

    - Test BOTH input formats

Unit test updates:

  - ValidatePdfHandlerTests.cs:

    - Update for Query + Handler co-location

    - Test AutoMapper integration

  - ExtractSwissQrCodeHandlerTests.cs:

    - Update for Query + Handler co-location

    - Test AutoMapper integration

Deleted:

  - DocumentEndpointsTests.cs (Minimal API tests, no longer relevant)

Result: 20/20 tests passing, Controller endpoint coverage

DocumentOperator.Tests/Integration/API/PdfValidationControllerTests.cs

@@ -0,0 +1,169 @@
+using DocumentOperator.Application.Common.DTOs;
+using DocumentOperator.Application.ValidatePdf.Queries;
+using FluentAssertions;
+using Microsoft.AspNetCore.Mvc.Testing;
+using System.Net;
+using System.Net.Http.Json;
+using Xunit;
+
+namespace DocumentOperator.Tests.Integration.API;
+
+public class PdfValidationControllerTests : IClassFixture<WebApplicationFactory<Program>>
+{
+    private readonly WebApplicationFactory<Program> _factory;
+    private readonly HttpClient _client;
+
+    public PdfValidationControllerTests(WebApplicationFactory<Program> factory)
+    {
+        _factory = factory;
+        _client = _factory.CreateClient();
+    }
+
+    #region Base64 JSON Tests
+
+    [Fact]
+    public async Task POST_ValidatePdf_Base64_ValidPdf_Returns200()
+    {
+        // Arrange
+        // Verwende ein echtes Test-PDF (embedded resource aus Unit Tests)
+        var assembly = typeof(PdfValidationControllerTests).Assembly;
+        var resourceName = "DocumentOperator.Tests.TestData.Pdfs.valid.pdf";
+
+        byte[] pdfBytes;
+        using (var stream = assembly.GetManifestResourceStream(resourceName))
+        {
+            if (stream == null)
+            {
+                throw new InvalidOperationException($"Test resource '{resourceName}' not found");
+            }
+
+            using var ms = new MemoryStream();
+            await stream.CopyToAsync(ms);
+            pdfBytes = ms.ToArray();
+        }
+
+        var base64Pdf = Convert.ToBase64String(pdfBytes);
+        var request = new ValidatePdfQuery { Base64Pdf = base64Pdf };
+
+        // Act
+        var response = await _client.PostAsJsonAsync("/api/pdf/validation/validate", request);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.OK);
+
+        var result = await response.Content.ReadFromJsonAsync<PdfValidationResult>();
+        result.Should().NotBeNull();
+        result!.PageCount.Should().BeGreaterThan(0);
+        result.FileSizeBytes.Should().BeGreaterThan(0);
+        result.PdfVersion.Should().NotBeNullOrEmpty();
+    }
+
+    [Fact]
+    public async Task POST_ValidatePdf_Base64_InvalidBase64_Returns400()
+    {
+        // Arrange
+        var request = new ValidatePdfQuery { Base64Pdf = "invalid-base64!!!" }; // Kein gültiges Base64
+
+        // Act
+        var response = await _client.PostAsJsonAsync("/api/pdf/validation/validate", request);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+
+        var problemDetails = await response.Content.ReadAsStringAsync();
+        problemDetails.Should().Contain("Base64");
+    }
+
+    [Fact]
+    public async Task POST_ValidatePdf_Base64_EmptyPdf_Returns400()
+    {
+        // Arrange
+        var request = new ValidatePdfQuery { Base64Pdf = string.Empty }; // Leerer String
+
+        // Act
+        var response = await _client.PostAsJsonAsync("/api/pdf/validation/validate", request);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+
+        var problemDetails = await response.Content.ReadAsStringAsync();
+        problemDetails.Should().Contain("Either PdfBytes or Base64Pdf must be provided");
+    }
+
+    #endregion
+
+    #region Multipart/Form-Data Tests
+
+    [Fact]
+    public async Task POST_ValidatePdf_Multipart_ValidPdf_Returns200()
+    {
+        // Arrange
+        var assembly = typeof(PdfValidationControllerTests).Assembly;
+        var resourceName = "DocumentOperator.Tests.TestData.Pdfs.valid.pdf";
+
+        byte[] pdfBytes;
+        using (var stream = assembly.GetManifestResourceStream(resourceName))
+        {
+            if (stream == null)
+            {
+                throw new InvalidOperationException($"Test resource '{resourceName}' not found");
+            }
+
+            using var ms = new MemoryStream();
+            await stream.CopyToAsync(ms);
+            pdfBytes = ms.ToArray();
+        }
+
+        // Create multipart/form-data content
+        using var content = new MultipartFormDataContent();
+        var fileContent = new ByteArrayContent(pdfBytes);
+        fileContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/pdf");
+        content.Add(fileContent, "file", "test.pdf");
+
+        // Act
+        var response = await _client.PostAsync("/api/pdf/validation/validate", content);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.OK);
+
+        var result = await response.Content.ReadFromJsonAsync<PdfValidationResult>();
+        result.Should().NotBeNull();
+        result!.PageCount.Should().BeGreaterThan(0);
+        result.FileSizeBytes.Should().BeGreaterThan(0);
+        result.PdfVersion.Should().NotBeNullOrEmpty();
+    }
+
+    [Fact]
+    public async Task POST_ValidatePdf_Multipart_EmptyFile_Returns400()
+    {
+        // Arrange
+        using var content = new MultipartFormDataContent();
+        var fileContent = new ByteArrayContent(Array.Empty<byte>());
+        fileContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/pdf");
+        content.Add(fileContent, "file", "empty.pdf");
+
+        // Act
+        var response = await _client.PostAsync("/api/pdf/validation/validate", content);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+
+        var problemDetails = await response.Content.ReadAsStringAsync();
+        problemDetails.Should().Contain("cannot be empty");
+    }
+
+    [Fact]
+    public async Task POST_ValidatePdf_Multipart_NoFile_Returns400()
+    {
+        // Arrange
+        using var content = new MultipartFormDataContent();
+
+        // Act
+        var response = await _client.PostAsync("/api/pdf/validation/validate", content);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+    }
+
+    #endregion
+}