feat: Add new provenance and crypto registry documentation

- Introduced attestation inventory and subject-rekor mapping files for tracking Docker packages.
- Added a comprehensive crypto registry decision document outlining defaults and required follow-ups.
- Created an offline feeds manifest for bundling air-gap resources.
- Implemented a script to generate and update binary manifests for curated binaries.
- Added a verification script to ensure binary artefacts are located in approved directories.
- Defined new schemas for AdvisoryEvidenceBundle, OrchestratorEnvelope, ScannerReportReadyPayload, and ScannerScanCompletedPayload.
- Established project files for StellaOps.Orchestrator.Schemas and StellaOps.PolicyAuthoritySignals.Contracts.
- Updated vendor manifest to track pinned binaries for integrity.

AGENTS.md

@@ -58,7 +58,7 @@ When you are told you are working in a particular module or directory, assume yo
 
 * **Runtime**: .NET 10 (`net10.0`) with latest C# preview features. Microsoft.* dependencies should target the closest compatible versions.
 * **Frontend**: Angular v17 for the UI.
-* **NuGet**: Re-use / cache packages into `/local-nugets` where possible.
+* **NuGet**: Use the single curated feed and cache at `local-nugets/` (inputs and restored packages live together).
 * **Data**: MongoDB as canonical store and for job/export state. Use a MongoDB driver version ≥ 3.0.
 * **Observability**: Structured logs, counters, and (optional) OpenTelemetry traces.
 * **Ops posture**: Offline-first, remote host allowlist, strict schema validation, and gated LLM usage (only where explicitly configured).