New canonical domain openspec/specs/prometheus-charting/spec.md with all
27 requirements (SC-101..127) as the durable post-change contract. Change-side
delta specs/prometheus-charting/spec.md + sync-report.md. web-ui canonical
untouched (different concern).
- Archive the completed observability-service-registry SDD change into
openspec/changes/archive/ (delivered across 5 slices; only
jellyfin-service-registry remains active).
- Stop ignoring .pi-map.md / .pi-map.index.md so the navigation maps are
versioned alongside the code, and add the regenerated map pairs repo-wide.