Refactor SurfaceCacheValidator to simplify oldest entry calculation

Add global using for Xunit in test project

Enhance ImportValidatorTests with async validation and quarantine checks

Implement FileSystemQuarantineServiceTests for quarantine functionality

Add integration tests for ImportValidator to check monotonicity

Create BundleVersionTests to validate version parsing and comparison logic

Implement VersionMonotonicityCheckerTests for monotonicity checks and activation logic

src/Scanner/StellaOps.Scanner.WebService/Services/IExportServices.cs

@@ -0,0 +1,36 @@
+using StellaOps.Scanner.WebService.Domain;
+
+namespace StellaOps.Scanner.WebService.Services;
+
+/// <summary>
+/// Service for exporting findings as SARIF.
+/// </summary>
+public interface ISarifExportService
+{
+    /// <summary>
+    /// Exports scan findings as a SARIF document.
+    /// </summary>
+    Task<object?> ExportAsync(ScanId scanId, CancellationToken cancellationToken = default);
+}
+
+/// <summary>
+/// Service for exporting findings as CycloneDX with reachability extension.
+/// </summary>
+public interface ICycloneDxExportService
+{
+    /// <summary>
+    /// Exports scan findings as CycloneDX with reachability annotations.
+    /// </summary>
+    Task<object?> ExportWithReachabilityAsync(ScanId scanId, CancellationToken cancellationToken = default);
+}
+
+/// <summary>
+/// Service for exporting VEX decisions as OpenVEX.
+/// </summary>
+public interface IOpenVexExportService
+{
+    /// <summary>
+    /// Exports VEX decisions for the scan as OpenVEX format.
+    /// </summary>
+    Task<object?> ExportAsync(ScanId scanId, CancellationToken cancellationToken = default);
+}