Add audit logging, processing stages, delete functionality, and bug fixes

- Add audit logging system for tracking CV uploads, processing, deletion,
  report views, and PDF exports for billing/reference purposes
- Add processing stage display on dashboard instead of generic "Processing"
- Add delete button for CV checks on dashboard
- Fix duplicate primary key error in CompanyCache (race condition)
- Fix DbContext concurrency in Dashboard (concurrent delete/load operations)
- Fix ProcessCVCheckJob to handle deleted records gracefully
- Fix duplicate flags in verification report by deduplicating on Title+Description
- Remove internal cache notes from verification results
- Add EF migrations for ProcessingStage and AuditLog table

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/TrueCV.Tests/Jobs/ProcessCVCheckJobTests.cs

@@ -20,6 +20,7 @@ public sealed class ProcessCVCheckJobTests : IDisposable
     private readonly Mock<ICompanyVerifierService> _companyVerifierServiceMock;
     private readonly Mock<IEducationVerifierService> _educationVerifierServiceMock;
     private readonly Mock<ITimelineAnalyserService> _timelineAnalyserServiceMock;
+    private readonly Mock<IAuditService> _auditServiceMock;
     private readonly Mock<ILogger<ProcessCVCheckJob>> _loggerMock;
     private readonly ProcessCVCheckJob _sut;
 
@@ -40,6 +41,7 @@ public sealed class ProcessCVCheckJobTests : IDisposable
         _companyVerifierServiceMock = new Mock<ICompanyVerifierService>();
         _educationVerifierServiceMock = new Mock<IEducationVerifierService>();
         _timelineAnalyserServiceMock = new Mock<ITimelineAnalyserService>();
+        _auditServiceMock = new Mock<IAuditService>();
         _loggerMock = new Mock<ILogger<ProcessCVCheckJob>>();
 
         _sut = new ProcessCVCheckJob(
@@ -49,6 +51,7 @@ public sealed class ProcessCVCheckJobTests : IDisposable
             _companyVerifierServiceMock.Object,
             _educationVerifierServiceMock.Object,
             _timelineAnalyserServiceMock.Object,
+            _auditServiceMock.Object,
             _loggerMock.Object);
     }
 

tests/TrueCV.Tests/Services/CVCheckServiceTests.cs

@@ -23,6 +23,7 @@ public sealed class CVCheckServiceTests : IDisposable
     private readonly ApplicationDbContext _dbContext;
     private readonly Mock<IFileStorageService> _fileStorageServiceMock;
     private readonly Mock<IBackgroundJobClient> _backgroundJobClientMock;
+    private readonly Mock<IAuditService> _auditServiceMock;
     private readonly Mock<ILogger<CVCheckService>> _loggerMock;
     private readonly CVCheckService _sut;
 
@@ -35,12 +36,14 @@ public sealed class CVCheckServiceTests : IDisposable
         _dbContext = new ApplicationDbContext(options);
         _fileStorageServiceMock = new Mock<IFileStorageService>();
         _backgroundJobClientMock = new Mock<IBackgroundJobClient>();
+        _auditServiceMock = new Mock<IAuditService>();
         _loggerMock = new Mock<ILogger<CVCheckService>>();
 
         _sut = new CVCheckService(
             _dbContext,
             _fileStorageServiceMock.Object,
             _backgroundJobClientMock.Object,
+            _auditServiceMock.Object,
             _loggerMock.Object);
     }