chore: archive observability-service-registry, track pi-map artifacts

- 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.

openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui/.pi-map.index.md

@@ -0,0 +1,19 @@
+# openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui (index)
+dir: openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui
+
+## role
+Defines durable architectural specifications and post-change contracts for a web UI rework transitioning from MUI/Emotion to shadcn/ui/Tailwind.
+## parent
+index: openspec/changes/archive/2026-06-17-web-ui-rework/specs/.pi-map.index.md
+map: openspec/changes/archive/2026-06-17-web-ui-rework/specs/.pi-map.md
+## children
+-
+## files
+- spec.md
+## links
+index: openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui/.pi-map.index.md
+map: openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui/.pi-map.md
+## workflows
+-
+## dirty
+-

openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui/.pi-map.md

@@ -0,0 +1,19 @@
+# openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui
+dir: openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui
+
+index: openspec/changes/archive/2026-06-17-web-ui-rework/specs/web-ui/.pi-map.index.md
+
+## role
+Defines durable architectural specifications and post-change contracts for a web UI rework transitioning from MUI/Emotion to shadcn/ui/Tailwind.
+## files
+- spec.md | Defines durable post-change end-state contracts for a web UI rework migrating from MUI/Emotion to shadcn/ui/Tailwind, removing charting, restructuring navigation, and standardizing on TanStack Table with Vitest testing. | dep: shadcn/ui, Tailwind v4, lucide-react, Radix primitives, @tanstack/react-table, react-router-dom, react-oidc-context, Vitest, @testing-library/react, Grafana
+## arch
+Specification document establishing declarative technology-stack mandates, component-library standards, and structural conventions governing frontend implementation.
+## tags
+react, shadcn, table, vitest, spec, defines, durable, post
+## symbols
+-
+## workflows
+-
+## dirty
+-