feat(rust): Implement RustCargoLockParser and RustFingerprintScanner

- Added RustCargoLockParser to parse Cargo.lock files and extract package information.
- Introduced RustFingerprintScanner to scan for Rust fingerprint records in JSON files.
- Created test fixtures for Rust language analysis, including Cargo.lock and fingerprint JSON files.
- Developed tests for RustLanguageAnalyzer to ensure deterministic output based on provided fixtures.
- Added expected output files for both simple and signed Rust applications.

src/StellaOps.Excititor.Attestation/EXCITITOR-ATTEST-01-003-plan.md

@@ -1,7 +1,7 @@
 # EXCITITOR-ATTEST-01-003 - Verification & Observability Plan
 
 - **Date:** 2025-10-19
-- **Status:** Draft
+- **Status:** In progress (2025-10-22)
 - **Owner:** Team Excititor Attestation
 - **Related tasks:** EXCITITOR-ATTEST-01-003 (Wave 0), EXCITITOR-WEB-01-003/004, EXCITITOR-WORKER-01-003
 - **Prerequisites satisfied:** EXCITITOR-ATTEST-01-002 (Rekor v2 client integration)
@@ -141,9 +141,17 @@ Metrics must register via static helper using `Meter` and support offline operat
 - Do we need cross-module eventing when verification fails (e.g., notify Export module) or is logging sufficient in Wave 0? (Proposed: log + metrics now, escalate in later wave.)
 - Confirm whether Worker re-verification writes to Mongo or triggers Export module to re-sign artifacts automatically; placeholder: record status + timestamp only.
 
-## 10. Acceptance Criteria
+## 10. Acceptance Criteria
 
 - Plan approved by Attestation + WebService + Worker leads.
 - Metrics/logging names peer-reviewed to avoid collisions.
 - Test backlog items entered into respective `TASKS.md` once implementation starts.
-- Documentation (this plan) linked from `TASKS.md` notes for discoverability.
+- Documentation (this plan) linked from `TASKS.md` notes for discoverability.
+
+## 11. 2025-10-22 Progress Notes
+
+- Implemented `IVexAttestationVerifier`/`VexAttestationVerifier` with structural validation (subject/predicate checks, digest comparison, Rekor probes) and diagnostics map.
+- Added `VexAttestationVerificationOptions` (RequireTransparencyLog, AllowOfflineTransparency, MaxClockSkew) and wired configuration through WebService DI.
+- Created `VexAttestationMetrics` (`excititor.attestation.verify_total`, `excititor.attestation.verify_duration_seconds`) and hooked into verification flow with component/rekor tags.
+- `VexAttestationClient.VerifyAsync` now delegates to the verifier; DI registers metrics + verifier via `AddVexAttestation`.
+- Added unit coverage in `VexAttestationVerifierTests` (happy path, digest mismatch, offline Rekor) and updated client/export/webservice stubs to new verification signature.