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.

docs/implplan/SPRINT_174_telemetry.md

@@ -7,9 +7,31 @@ Depends on: Sprint 150.A - Orchestrator
 Summary: Notifications & Telemetry focus on Telemetry).
 Task ID | State | Task description | Owners (Source)
 --- | --- | --- | ---
-TELEMETRY-OBS-50-001 | TODO | Create `StellaOps.Telemetry.Core` library with structured logging facade, OpenTelemetry configuration helpers, and deterministic bootstrap (service name/version detection, resource attributes). Publish sample usage for web/worker hosts. | Telemetry Core Guild (src/Telemetry/StellaOps.Telemetry.Core)
+TELEMETRY-OBS-50-001 | **DOING (2025-11-12)** | Create `StellaOps.Telemetry.Core` library with structured logging facade, OpenTelemetry configuration helpers, and deterministic bootstrap (service name/version detection, resource attributes). Publish sample usage for web/worker hosts. | Telemetry Core Guild (src/Telemetry/StellaOps.Telemetry.Core)
 TELEMETRY-OBS-50-002 | TODO | Implement context propagation middleware/adapters for HTTP, gRPC, background jobs, and CLI invocations, carrying `trace_id`, `tenant_id`, `actor`, and imposed-rule metadata. Provide test harness covering async resume scenarios. Dependencies: TELEMETRY-OBS-50-001. | Telemetry Core Guild (src/Telemetry/StellaOps.Telemetry.Core)
 TELEMETRY-OBS-51-001 | TODO | Ship metrics helpers for golden signals (histograms, counters, gauges) with exemplar support and cardinality guards. Provide Roslyn analyzer preventing unsanitised labels. Dependencies: TELEMETRY-OBS-50-002. | Telemetry Core Guild, Observability Guild (src/Telemetry/StellaOps.Telemetry.Core)
 TELEMETRY-OBS-51-002 | TODO | Implement redaction/scrubbing filters for secrets/PII enforced at logger sink, configurable per-tenant with TTL, including audit of overrides. Add determinism tests verifying stable field order and timestamp normalization. Dependencies: TELEMETRY-OBS-51-001. | Telemetry Core Guild, Security Guild (src/Telemetry/StellaOps.Telemetry.Core)
 TELEMETRY-OBS-55-001 | TODO | Provide incident mode toggle API that adjusts sampling, enables extended retention tags, and records activation trail for services. Ensure toggle honored by all hosting templates and integrates with Config/FeatureFlag providers. Dependencies: TELEMETRY-OBS-51-002. | Telemetry Core Guild (src/Telemetry/StellaOps.Telemetry.Core)
-TELEMETRY-OBS-56-001 | TODO | Add sealed-mode telemetry helpers (drift metrics, seal/unseal spans, offline exporters) and ensure hosts can disable external exporters when sealed. Dependencies: TELEMETRY-OBS-55-001. | Telemetry Core Guild (src/Telemetry/StellaOps.Telemetry.Core)
+TELEMETRY-OBS-56-001 | TODO | Add sealed-mode telemetry helpers (drift metrics, seal/unseal spans, offline exporters) and ensure hosts can disable external exporters when sealed. Dependencies: TELEMETRY-OBS-55-001. | Telemetry Core Guild (src/Telemetry/StellaOps.Telemetry.Core)
+
+## Status notes (2025-11-12 UTC)
+
+- **TELEMETRY-OBS-50-001** – Core bootstrap scaffolding live in branch `feature/telemetry-core-bootstrap`; resource detector + profile manifest generator in review; sample Orchestrator host integration slated for 2025-11-18.
+- **TELEMETRY-OBS-50-002** – Awaiting merged bootstrap package before wiring propagation adapters; draft design covers HTTP/gRPC/job/CLI interceptors plus tenant/actor propagation tests.
+- **TELEMETRY-OBS-51-001/51-002** – On hold until propagation middleware stabilizes; Security Guild still reviewing scrub policy (POLICY-SEC-42-003).
+- **TELEMETRY-OBS-55-001/56-001** – Incident/sealed-mode APIs blocked on CLI toggle contract (CLI-OBS-12-001) and Notify incident payload spec (NOTIFY-OBS-55-001); keep coordination with Notifier team.
+
+## Milestones & dependencies
+
+| Target date | Milestone | Owner(s) | Notes / dependencies |
+| --- | --- | --- | --- |
+| 2025-11-18 | Land Telemetry.Core bootstrap sample in Orchestrator | Telemetry Core Guild · Orchestrator Guild | Demonstrates TELEMETRY-OBS-50-001 deliverable; prerequisite for propagation middleware adoption. |
+| 2025-11-19 | Publish propagation adapter API draft | Telemetry Core Guild | Needed for TELEMETRY-OBS-50-002 and downstream service adoption. |
+| 2025-11-21 | Security sign-off on scrub policy (POLICY-SEC-42-003) | Telemetry Core Guild · Security Guild | Unlocks TELEMETRY-OBS-51-001/51-002 implementation. |
+| 2025-11-22 | Incident/CLI toggle contract agreed (CLI-OBS-12-001 + NOTIFY-OBS-55-001) | Telemetry Core Guild · Notifications Service Guild · CLI Guild | Required before TELEMETRY-OBS-55-001/56-001 can advance. |
+
+## Coordination log
+
+| Date (UTC) | Update | Owner |
+| --- | --- | --- |
+| 2025-11-12 18:05 | Marked TELEMETRY-OBS-50-001 as DOING and captured branch/progress details in status notes. | Telemetry Core Guild |