Implement ledger metrics for observability and add tests for Ruby packages endpoints

- Added `LedgerMetrics` class to record write latency and total events for ledger operations.
- Created comprehensive tests for Ruby packages endpoints, covering scenarios for missing inventory, successful retrieval, and identifier handling.
- Introduced `TestSurfaceSecretsScope` for managing environment variables during tests.
- Developed `ProvenanceMongoExtensions` for attaching DSSE provenance and trust information to event documents.
- Implemented `EventProvenanceWriter` and `EventWriter` classes for managing event provenance in MongoDB.
- Established MongoDB indexes for efficient querying of events based on provenance and trust.
- Added models and JSON parsing logic for DSSE provenance and trust information.

src/Scanner/__Libraries/StellaOps.Scanner.Analyzers.Lang.Ruby/TASKS.md

@@ -2,7 +2,7 @@
 
 | Task ID | State | Notes |
 | --- | --- | --- |
-| `SCANNER-ENG-0009` | DOING (2025-11-12) | Added bundler-version metadata + observation summaries, richer CLI output, and the `complex-app` fixture to drive parity validation. |
+| `SCANNER-ENG-0009` | DONE (2025-11-13) | Ruby analyzer parity landed end-to-end: Mongo-backed `ruby.packages` inventories, WebService `/api/scans/{scanId}/ruby-packages`, CLI `ruby resolve` + observations, plugin manifest packaging, and targeted tests (`StellaOps.Scanner.Analyzers.Lang.Ruby.Tests`, `StellaOps.Scanner.Worker.Tests`, `StellaOps.Scanner.WebService.Tests --filter FullyQualifiedName~RubyPackages`). |
 | `SCANNER-ENG-0016` | DONE (2025-11-10) | RubyLockCollector merged with vendor cache ingestion; workspace overrides, bundler groups, git/path fixture, and offline-kit mirror updated. |
 | `SCANNER-ENG-0017` | DONE (2025-11-09) | Build runtime require/autoload graph builder with tree-sitter Ruby per design §4.4, feed EntryTrace hints. |
 | `SCANNER-ENG-0018` | DONE (2025-11-09) | Emit Ruby capability + framework surface signals, align with design §4.5 / Sprint 138. |