Follow-up #1 to the service-registry change. Jellyfin/Jellyseerr now resolve
from the service registry, so the machine-level app fields are dead config.
- dependencies.py: drop dead _jellyseerr_client_for; simplify _resolve_machine
to SSH-only.
- settings_store.py + routers/settings.py: remove jellyfin_*/jellyseerr_* from
machine default config, get_machine_config, normalization, row mappers, and
MachineInput.
- frontend types + Settings.tsx: drop the fields and the Jellyfin/Jellyseerr
form sections + service options.
- Update frontend test fixtures.
Existing DB rows may still carry these keys in config_json; they are inert and
drop on the next machine save. Verification: backend ruff clean, pytest 222;
frontend lint 0 errors, build success, 70 tests.
Refactor SSHKeyManager to match app layout pattern:
- List of SSH keys on the left (SelectionRailCard)
- Key details and form on the right (SectionCard)
- Add selectedSSHKeyId state to Settings component
- Click a key to select and populate the form
- New key button to create a new key
- Shows fingerprint and public key for selected key
- Delete button moved to the right panel