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/Excititor/StellaOps.Excititor.Connectors.StellaOpsMirror/TASKS.md

@@ -1,6 +0,0 @@
-# StellaOps Mirror VEX Connector Task Board (Sprint 7)
-
-| ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
-|----|--------|----------|------------|-------------|---------------|
-| EXCITITOR-CONN-STELLA-07-002 | TODO | Excititor Connectors – Stella | EXCITITOR-CONN-STELLA-07-001 | Parse mirror bundles into raw `VexClaim` batches, preserving original provider metadata and mirror provenance without applying consensus or weighting. | Normalizer emits deterministic VexClaims with full provenance (no policy metadata), fixtures assert parity with source exports. |
-| EXCITITOR-CONN-STELLA-07-003 | TODO | Excititor Connectors – Stella | EXCITITOR-CONN-STELLA-07-002 | Implement incremental cursor handling per-export digest for raw claim replays, support resume, and document configuration for downstream Excititor mirrors. | Connector resumes from last export digest, handles delta/export rotation, docs show configuration; integration test covers resume + raw ingest parity. |