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/evidence-locker/crypto-provider-registry-prep.md

@@ -0,0 +1,21 @@
+# ICryptoProviderRegistry Prep — PREP-EVID-CRYPTO-90-001 (Draft)
+
+Status: Draft (2025-11-20)
+Owners: Evidence Locker Guild · Security Guild
+Scope: Capture requirements for crypto provider registry readiness to support sovereign/region-specific profiles.
+
+## Required capabilities
+- Registry interface to resolve crypto providers by profile ID (e.g., `default`, `ru-offline`, `fips140`, `eidass`).
+- Provider metadata: `{algorithms[], key_formats[], offline_supported, hsm_supported, oq_ready}`.
+- Deterministic selection rules: prefer tenant-scoped overrides, fall back to platform defaults; no network fetch.
+
+## Integration points
+- Evidence Locker signing pipeline to request provider by profile when sealing bundles.
+- Replay validation to know which algorithms/hashes are acceptable for DSSE verification.
+
+## Dependencies
+- Final list of sovereign profiles from Security Guild.
+- Key storage/backing (KMS/HSM) availability per profile.
+
+## Handoff
+Use this as the prep artefact for PREP-EVID-CRYPTO-90-001; update once profile list and key storage rules are confirmed.