feat(telemetry): pack ZB.MOM.WW.Telemetry 0.1.0 + README/CLAUDE + register observability component in indexes

- NuGet metadata: expanded Description and PackageTags on both library csproj files
  (opentelemetry;observability;metrics;tracing;prometheus;otlp;... / serilog;logging;...)
- Full dotnet test: 7 (Telemetry) + 12 (Serilog) = 19 tests, all green
- dotnet pack: ZB.MOM.WW.Telemetry.0.1.0.nupkg + ZB.MOM.WW.Telemetry.Serilog.0.1.0.nupkg
  (artifacts/ gitignored, not committed)
- ZB.MOM.WW.Telemetry/README.md: overview, 2 packages, unifying hinge prose,
  exporter options, OTel signals + trace-log correlation, test/pack commands, status
- ZB.MOM.WW.Telemetry/CLAUDE.md: package responsibilities, consumer matrix,
  build/test/pack commands, status + pointers to components/observability/
- components/README.md: Observability row added to component registry table
- CLAUDE.md: Telemetry row added to component-normalization table; intro count
  updated to four shared libs; observability prose paragraph added (MxGateway
  logging adoption noted)
- upcoming.md: Observability item ticked done, pointing at components/observability/
  and ZB.MOM.WW.Telemetry; MxGateway MEL->Serilog adoption noted
- components/observability/README.md: status updated to Built @ 0.1.0, library
  build/pack commands added, MxGateway adoption row updated

upcoming.md

@@ -86,5 +86,10 @@ cross-repo interop checks, distinct from the others.
    0.1.0 (3 packages, 58 tests). Design: [`components/health/`](components/health/);
    implementation: [`../ZB.MOM.WW.Health/`](../ZB.MOM.WW.Health/). Adoption tracked in
    [`components/health/GAPS.md`](components/health/GAPS.md).
-2. **Observability/telemetry** (completes the operability cluster with Health). 3. **Audit model**
-   (ties back to Auth). Then revisit the gRPC contract surface and the `Hosting` aggregator.
+2. ~~**Observability/telemetry** (completes the operability cluster with Health).~~ **Done** —
+   `ZB.MOM.WW.Telemetry` built @ 0.1.0 (2 packages, 19 tests). Design:
+   [`components/observability/`](components/observability/); implementation:
+   [`../ZB.MOM.WW.Telemetry/`](../ZB.MOM.WW.Telemetry/). MxAccessGateway MEL → Serilog
+   logging adoption done on its own branch. Broader OtOpcUa/ScadaBridge telemetry adoption
+   tracked in [`components/observability/GAPS.md`](components/observability/GAPS.md).
+3. **Audit model** (ties back to Auth). Then revisit the gRPC contract surface and the `Hosting` aggregator.