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/specs/.pi-map.index.md

@@ -0,0 +1,20 @@
+# openspec/specs (index)
+dir: openspec/specs
+
+## role
+Directory for OpenAPI/Swagger specification files defining API contracts, schemas, and endpoint documentation.
+## parent
+index: openspec/.pi-map.index.md
+map: openspec/.pi-map.md
+## children
+- openspec/specs/web-ui
+  index: openspec/specs/web-ui/.pi-map.index.md
+  map: openspec/specs/web-ui/.pi-map.md
+## files
+## links
+index: openspec/specs/.pi-map.index.md
+map: openspec/specs/.pi-map.md
+## workflows
+-
+## dirty
+-

openspec/specs/.pi-map.md

@@ -0,0 +1,18 @@
+# openspec/specs
+dir: openspec/specs
+
+index: openspec/specs/.pi-map.index.md
+
+## role
+Directory for OpenAPI/Swagger specification files defining API contracts, schemas, and endpoint documentation.
+## files
+## arch
+Declarative YAML/JSON specification files following the OpenAPI standard, organized as static schema definitions without executable code.
+## tags
+-
+## symbols
+-
+## workflows
+-
+## dirty
+-

openspec/specs/web-ui/.pi-map.index.md

@@ -0,0 +1,19 @@
+# openspec/specs/web-ui (index)
+dir: openspec/specs/web-ui
+
+## role
+Canonical specification document defining the web UI migration plan from MUI/Emotion to shadcn/ui + Tailwind v4 with TanStack Table and observability tooling.
+## parent
+index: openspec/specs/.pi-map.index.md
+map: openspec/specs/.pi-map.md
+## children
+-
+## files
+- spec.md
+## links
+index: openspec/specs/web-ui/.pi-map.index.md
+map: openspec/specs/web-ui/.pi-map.md
+## workflows
+-
+## dirty
+-

openspec/specs/web-ui/.pi-map.md

@@ -0,0 +1,19 @@
+# openspec/specs/web-ui
+dir: openspec/specs/web-ui
+
+index: openspec/specs/web-ui/.pi-map.index.md
+
+## role
+Canonical specification document defining the web UI migration plan from MUI/Emotion to shadcn/ui + Tailwind v4 with TanStack Table and observability tooling.
+## files
+- spec.md | Defines the canonical post-rework specification for a Manage web frontend migration from MUI/Emotion to shadcn/ui + Tailwind v4, with TanStack Table data grids, thin-dashboard observability, and reconciled information architecture. | dep: shadcn/ui, Tailwind v4, lucide-react, TanStack Table, @tanstack/react-table, Radix primitives, react-router-dom, react-oidc-context, Vitest, @testing-library/react, Grafana
+## arch
+Single-document declarative specification (no code architecture); describes target frontend stack patterns including component library migration, data grid implementation, and information architecture reconciliation.
+## tags
+react, shadcn, table, spec, defines, canonical, post, rework
+## symbols
+-
+## workflows
+-
+## dirty
+-