Add LDAP Distinguished Name Helper and Credential Audit Context

- Implemented LdapDistinguishedNameHelper for escaping RDN and filter values.
- Created AuthorityCredentialAuditContext and IAuthorityCredentialAuditContextAccessor for managing credential audit context.
- Developed StandardCredentialAuditLogger with tests for success, failure, and lockout events.
- Introduced AuthorityAuditSink for persisting audit records with structured logging.
- Added CryptoPro related classes for certificate resolution and signing operations.

src/Graph/StellaOps.Graph.Indexer/TASKS.md

@@ -1,14 +0,0 @@
-# Graph Indexer Task Board — Epic 5: SBOM Graph Explorer
-| ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
-|----|--------|----------|------------|-------------|---------------|
-| GRAPH-INDEX-28-001 | DONE (2025-11-03) | Graph Indexer Guild | SBOM-SERVICE-21-001, CARTO-GRAPH-21-001 | Define canonical node/edge schemas, attribute dictionaries, identity rules, and seed fixtures; publish schema doc.<br>2025-11-03: Schema doc v1 published, fixtures added (`nodes.json`, `edges.json`, `schema-matrix.json`), GraphIdentity determinism tests green. | Schema doc merged; identity property tests pass; fixtures committed for CI usage. |
-| GRAPH-INDEX-28-002 | DONE (2025-11-03) | Graph Indexer Guild | GRAPH-INDEX-28-001, SBOM-SERVICE-21-002 | Implement SBOM ingest consumer producing artifact/package/file nodes and edges with `valid_from/valid_to`, scope metadata, and provenance links.<br>2025-11-03: Snapshot models repaired, provenance resolution tightened, ingest processor/metrics surfaces added, and transformer/fixtures/tests expanded for license/base artifact determinism. | Ingest pipeline processes sample SBOMs deterministically; metrics recorded; unit tests cover identity stability. |
-| GRAPH-INDEX-28-003 | DONE (2025-11-03) | Graph Indexer Guild | GRAPH-INDEX-28-001, CONCELIER-CONSOLE-23-001 | Project Concelier linksets into overlay tiles (`affected_by` edges, evidence refs) without mutating source observations; keep advisory aggregates in overlay store only.<br>2025-11-03: Snapshot model repaired, transformer finalized with dedupe + provenance normalization, fixtures/tests refreshed, full graph suite green. | Overlay documents generated deterministically; raw node/edge collections remain immutable; tests cover overlay refresh and eviction. |
-| GRAPH-INDEX-28-004 | DONE (2025-11-03) | Graph Indexer Guild | GRAPH-INDEX-28-001, EXCITITOR-CONSOLE-23-001 | Integrate VEX statements (`vex_exempts` edges) with justification metadata and precedence markers for overlays.<br>2025-11-03: VEX snapshot/transformer emit deterministic VEX_EXEMPTS overlays with provenance hashes; fixtures and tests updated; full graph indexer suite green. | VEX edges generated; conflicts resolved deterministically; tests cover status transitions. |
-| GRAPH-INDEX-28-005 | DONE (2025-11-03) | Graph Indexer Guild, Policy Guild | POLICY-ENGINE-27-001, POLICY-ENGINE-27-002 | Hydrate policy overlays into graph (`governs_with` nodes/edges) referencing effective findings and explain hashes for sampled nodes.<br>2025-11-03: Policy overlay snapshot/transformer added with deterministic nodes/edges, fixtures + tests updated, targeted graph tests pass; Mongo writer tests now probe `STELLAOPS_TEST_MONGO_URI` or localhost before falling back to Mongo2Go and skip with guidance when neither path is available.<br>2025-11-03: Processor + metrics wired atop Mongo writer; unit tests cover success/failure paths. | Overlay nodes stored with policy version id, severity, status; explain references captured; validation tests pass. |
-| GRAPH-INDEX-28-006 | DONE (2025-11-03) | Graph Indexer Guild | GRAPH-INDEX-28-002..005 | Generate graph snapshots per SBOM with lineage (`derived_from`), adjacency manifests, and metadata for diff jobs.<br>2025-11-03: Snapshot builder emits hashed manifest + adjacency (incoming/outgoing edges), integration tests cover lineage/diff readiness, docs updated with required Mongo env.<br>2025-11-03: Snapshot exporter writes manifest/adjacency/nodes/edges to snapshot directory with deterministic ordering. | Snapshot documents produced; lineage recorded; tests assert diff readiness; metrics emitted. |
-| GRAPH-INDEX-28-007 | TODO | Graph Indexer Guild, Observability Guild | GRAPH-INDEX-28-002..006 | Implement clustering/centrality background jobs (Louvain/degree/betweenness approximations) with configurable schedules and store cluster ids on nodes. | Clustering jobs run on fixtures; metrics logged; cluster ids accessible via API; SLA documented. |
-| GRAPH-INDEX-28-008 | TODO | Graph Indexer Guild | GRAPH-INDEX-28-002..007 | Provide incremental update + backfill pipeline with change streams, retry/backoff, idempotent operations, and backlog metrics. | Incremental updates replay sample change logs; retries/backoff validated; backlog metrics exported. |
-| GRAPH-INDEX-28-009 | TODO | Graph Indexer Guild, QA Guild | GRAPH-INDEX-28-002..008 | Add unit/property/integration tests, synthetic large graph fixtures, chaos testing (missing overlays, cycles), and determinism checks across runs. | Test suite green; determinism harness passes across two runs; perf metrics recorded. |
-| GRAPH-INDEX-28-010 | TODO | Graph Indexer Guild, DevOps Guild | GRAPH-INDEX-28-008 | Package deployment artifacts (Helm/Compose), offline seed bundles, and configuration docs; integrate  Offline Kit. | Deployment descriptors merged; offline seed bundle documented; smoke deploy tested. |
-| GRAPH-INDEX-28-011 | DONE (2025-11-04) | Graph Indexer Guild | GRAPH-INDEX-28-002..006 | Wire SBOM ingest runtime to emit graph snapshot artifacts and harden Mongo test configuration.<br>2025-11-04: Adopted `SbomIngestProcessorFactory.CreateDefault` inside a DI extension, added configurable snapshot root (`STELLAOPS_GRAPH_SNAPSHOT_DIR` or options), documented Mongo/snapshot env guidance, and verified Graph Indexer tests (Mongo writer skipped when no URI). | Composition root uses factory/exporter, snapshot files land in configured artifacts directory, and dev/CI guidance ensures Mongo availability without manual edits. |