Add unit tests for SBOM ingestion and transformation

- Implement `SbomIngestServiceCollectionExtensionsTests` to verify the SBOM ingestion pipeline exports snapshots correctly.
- Create `SbomIngestTransformerTests` to ensure the transformation produces expected nodes and edges, including deduplication of license nodes and normalization of timestamps.
- Add `SbomSnapshotExporterTests` to test the export functionality for manifest, adjacency, nodes, and edges.
- Introduce `VexOverlayTransformerTests` to validate the transformation of VEX nodes and edges.
- Set up project file for the test project with necessary dependencies and configurations.
- Include JSON fixture files for testing purposes.

docs/modules/cli/architecture.md

@@ -128,10 +128,14 @@ src/
   * Imports a previously exported bundle into the local KMS root (`kms/` by default), promotes the imported version to `Active`, and preserves existing versions by marking them `PendingRotation`. Prompts for the passphrase when not provided to keep automation password-safe.
 
 Both subcommands honour offline-first expectations (no network access) and normalise relative roots via `--root` when operators mirror the credential store.
-
----
-
-## 3) AuthN: Authority + DPoP
+
+### 2.11 Air-gap guard
+
+- CLI outbound HTTP flows (Authority auth, backend APIs, advisory downloads) route through `StellaOps.AirGap.Policy`. When sealed mode is active the CLI refuses commands that would require external egress and surfaces the shared `AIRGAP_EGRESS_BLOCKED` remediation guidance instead of attempting the request.
+
+---
+
+## 3) AuthN: Authority + DPoP
 
 ### 3.1 Token acquisition