# Proposal — Jellyfin service-registry migration (completion)

**Change:** `jellyfin-service-registry`
**Phase:** proposal
**Date:** 2026-06-23

## Problem

The service-registry foundation already moved Jellyfin/Jellyseerr resolution into `dependencies.py` (`get_jellyfin_client`, `get_jellyseerr_client`, `get_user_id`) using `jellyfin_service_id`. The frontend `Applications`, `Media`, and `Users` pages already consume `useServiceInstances("jellyfin")`.

However, the **machine-level config still carries legacy Jellyfin DNA** that is now dead or misleading:

- `DEFAULT_SERVICES = ["monitoring", "files", "jellyfin"]` in `settings_store.py` auto-tags every local machine as a Jellyfin source.
- The Settings machine editor still exposes `services` multi-select that can include `jellyfin`, even though Jellyfin is selected via the Services page, not via a machine.
- `MonitoringMachine` types still carry `media_root` and `path_prefix` fields whose original purpose was Jellyfin→SSH path mapping, but the path-mapping logic in `path_utils.py` now operates independently and those fields are no longer read by the media/file flows.
- Documentation still describes machine-level Jellyfin fields in places.

This creates UI confusion (two places to think about Jellyfin) and stale surface area.

## Goal

Cleanly complete the Jellyfin migration onto the service registry:

1. Remove Jellyfin from the machine `services` taxonomy entirely.
2. Remove dead `media_root` / `path_prefix` machine fields from backend, frontend types, Settings form, and tests.
3. Update path-resolution helpers to rely only on the Jellyfin service config (or explicit path-prefix settings on the service record if needed), not on machine fields.
4. Update docs and changelog.

## Non-goals

- Do NOT change how Jellyfin/Jellyseerr clients are resolved in `dependencies.py` — that is already correct.
- Do NOT remove the `jellyfin` / `jellyseerr` service definitions.
- Do NOT add new service types or widgets in this change.

## Acceptance

- `grep -R "media_root\|path_prefix" backend/src frontend/src` returns only `path_utils.py` and its tests (if those helpers remain) or nothing (if the helpers are removed).
- `jellyfin` no longer appears in machine `services` options in the Settings UI.
- `DEFAULT_SERVICES` no longer includes `jellyfin`.
- Backend and frontend test suites remain green.
- Docs/CHANGELOG explain the final migration.