Add new features and tests for AirGap and Time modules

- Introduced `SbomService` tasks documentation.
- Updated `StellaOps.sln` to include new projects: `StellaOps.AirGap.Time` and `StellaOps.AirGap.Importer`.
- Added unit tests for `BundleImportPlanner`, `DsseVerifier`, `ImportValidator`, and other components in the `StellaOps.AirGap.Importer.Tests` namespace.
- Implemented `InMemoryBundleRepositories` for testing bundle catalog and item repositories.
- Created `MerkleRootCalculator`, `RootRotationPolicy`, and `TufMetadataValidator` tests.
- Developed `StalenessCalculator` and `TimeAnchorLoader` tests in the `StellaOps.AirGap.Time.Tests` namespace.
- Added `fetch-sbomservice-deps.sh` script for offline dependency fetching.

docs/modules/export-center/prep/2025-11-20-exporter-evid-blocker.md

@@ -0,0 +1,15 @@
+# Exporter Service Blocker — PREP-EXPORTER-SERVICE-BLOCKED-WAITING-ON-EVID
+
+Status: Draft (2025-11-20)
+Owners: Planning
+Scope: Document EvidenceLocker dependency blocking exporter service.
+
+## Blocker
+- EvidenceLocker spec not published; need replay/export bundle schemas and ICryptoProviderRegistry availability.
+
+## What we need
+- Bundle schema pointers (from EvidenceLocker) and retention rules.
+- Sample payloads to mirror into exporter tests.
+
+## Handoff
+Use this note to track unblock; update when EvidenceLocker spec is available.