Add Authority Advisory AI and API Lifecycle Configuration

- Introduced AuthorityAdvisoryAiOptions and related classes for managing advisory AI configurations, including remote inference options and tenant-specific settings.
- Added AuthorityApiLifecycleOptions to control API lifecycle settings, including legacy OAuth endpoint configurations.
- Implemented validation and normalization methods for both advisory AI and API lifecycle options to ensure proper configuration.
- Created AuthorityNotificationsOptions and its related classes for managing notification settings, including ack tokens, webhooks, and escalation options.
- Developed IssuerDirectoryClient and related models for interacting with the issuer directory service, including caching mechanisms and HTTP client configurations.
- Added support for dependency injection through ServiceCollectionExtensions for the Issuer Directory Client.
- Updated project file to include necessary package references for the new Issuer Directory Client library.

etc/packs-registry.yaml.sample

@@ -0,0 +1,62 @@
+# StellaOps Packs Registry configuration template.
+# Copy to ../etc/packs-registry.yaml (relative to the Packs Registry content root)
+# and adjust values as needed. Environment variables prefixed with
+# STELLAOPS_PACKSREGISTRY_ override these settings at runtime.
+
+schemaVersion: 1
+
+telemetry:
+  enabled: true
+  serviceName: "stellaops-packs-registry"
+  exportConsole: true
+  minimumLogLevel: "Information"
+  otlpEndpoint: ""
+  resourceAttributes:
+    deployment.environment: "local"
+
+authority:
+  issuer: "https://authority.stella-ops.local"
+  metadataAddress: ""
+  requireHttpsMetadata: true
+  audiences:
+    - "api://packs-registry"
+  tenant: "tenant-default"
+  # Client credentials for publishing packs into the registry.
+  publishClient:
+    clientId: "packs-registry"
+    clientSecret: ""
+    clientSecretFile: "../secrets/packs-registry.secret"
+    scopes:
+      - "packs.write"
+      - "packs.read"
+  # Optional read-only client for mirrors or offline tooling.
+  readerClient:
+    clientId: "packs-reader"
+    clientSecret: ""
+    clientSecretFile: "../secrets/packs-reader.secret"
+    scopes:
+      - "packs.read"
+
+storage:
+  # Mongo database storing pack metadata and provenance.
+  mongoConnectionString: "mongodb://packs-registry:registry@mongo:27017/packs-registry?authSource=admin"
+  # Object storage bucket/container for pack bundles and signatures.
+  bundleStore: "s3://stellaops-packs"
+
+signing:
+  # Trusted keys (PEM paths or Fulcio issuer URLs) used to validate inbound packs.
+  trustedKeys:
+    - "../certificates/packs-signing.pem"
+  # Enforce DSSE attestations for published packs.
+  requireDsse: true
+
+mirroring:
+  enabled: false
+  # Remote registry or file share used to seed mirrors in offline deployments.
+  source: ""
+  schedule: "00:30:00"
+
+offlineKit:
+  enabled: true
+  exportDirectory: "out/offline/packs"
+  provenanceManifest: "out/offline/packs/provenance.json"