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.

.pi-map.md

@@ -0,0 +1,45 @@
+# .
+dir: .
+
+index: ./.pi-map.index.md
+
+## Project Map Protocol
+
+1. Read this protocol and the root `.pi-map.index.md` first.
+2. Use `index:` / `map:` references to open relevant directory indexes and maps.
+3. Load indexes before rich maps during task-start navigation.
+4. Read the local rich map and actual source before editing.
+5. Treat non-empty `## dirty` sections in either artifact as stale.
+6. If source and generated artifacts disagree, trust source.
+7. If map and index disagree, trust neither blindly; verify from source and regenerate the pair.
+8. After editing source, run `project_map_patch` for each changed file.
+9. Before broad architectural claims or final handoff, run `project_map_validate` when freshness matters.
+
+Trust boundary: index routes, map orients, source decides.
+
+## role
+Root project configuration and documentation hub for "Manage," a media and server operations tool with a FastAPI + React architecture and optional observability stack.
+## files
+- .dockerignore | Specifies files and directories to exclude from Docker build context to reduce image size and improve build performance | dep: Docker
+- .env.example | Provides a template of environment variables for configuring application hosts, backend settings, OIDC authentication, SMTP, Grafana, and alerting across a Docker Compose deployment.
+- .gitignore | Specifies patterns for Git to ignore across a Python/Streamlit project with frontend components and internal tooling | dep: git, python, streamlit, node/npm
+- AGENTS.md | Provides project-specific guidance for AI agents working on a media library viewer application with FastAPI backend and Vite React frontend | dep: FastAPI, Vite, React, Docker Compose, uvicorn, pytest, Ruff, TypeScript, Python 3.11
+- CHANGELOG.md | Documents notable changes, breaking changes, and migration steps for the Manage project across versions.
+- CONTRIBUTING.md | Provides guidelines for setting up a development environment, coding standards, validation steps, and contribution requirements for a Streamlit-based media library viewer application. | dep: python, venv, pip, streamlit, py_compile
+- LICENSE | Provides the MIT open-source software license terms for the project
+- README.md | This file is the project README, serving as the primary documentation and setup guide for "Manage," a media and server operations tool with a FastAPI + React architecture. | dep: FastAPI, React, Jellyfin, Docker Compose, SQLite, Prometheus, Grafana, Alertmanager
+- context.md | Documentation file providing a historical and architectural overview of an observability stack (Prometheus, Grafana, Loki, Alertmanager) for a containerized media management application. | dep: Prometheus, Grafana, Loki, Alertmanager, Grafana Alloy, Node Exporter, Docker Compose, FastAPI
+- docker-compose.dev.yml | Defines a development Docker Compose stack for a backend (FastAPI/Uvicorn) and frontend (Vite) application with hot-reload and disabled authentication. | dep: uvicorn, Docker
+- docker-compose.observability.yml | Defines an optional standalone Docker Compose observability stack with Prometheus, Loki, Grafana, Alertmanager, Alloy, and Node Exporter for monitoring hosts without the main Manage application. | dep: prom/prometheus, grafana/loki, grafana/alloy, grafana/grafana, prom/alertmanager, prom/node-exporter, Traefik
+- docker-compose.yml | Defines a Docker Compose production stack for a backend and frontend application with OIDC authentication, Traefik reverse proxy routing, and Prometheus metrics exposure. | dep: Traefik, OIDC provider, Docker, SMTP server, external observability stack (Prometheus/Grafana/Loki/Alertmanager)
+- token-usage-output.txt | Displays a detailed token usage and cost analysis report for an AI coding session, including breakdowns by category, tool usage, cache efficiency, subagent costs, and pricing comparisons.
+## arch
+Docker Compose orchestrated multi-service architecture featuring a Python/FastAPI backend, Vite/React frontend, Traefik reverse proxy, and an optional Prometheus/Grafana/Loki monitoring stack.
+## tags
+docker, grafana, application, compose, fastapi, prometheus, project, alertmanager
+## symbols
+-
+## workflows
+-
+## dirty
+-