[Bug] Immich "provided by administrator" badge points to a setting no admin can reach

[Abrechen2]

Summary

The user Immich settings card can show a "Provided by the administrator" badge, but there is no admin UI anywhere to actually configure a global Immich instance.

What should have happened?

An admin should be able to set a global Immich base URL + API key from the admin area — analogous to the global flight API keys — so that users inherit a shared instance without pasting their own credentials.

Steps to reproduce

1. Log in as admin, open the admin area → there is no Immich section anywhere.
2. Open Settings → API keys → the Immich card exposes the "shared" badge path but only offers a personal connection.

TravStats version

2.3.0-immich-beta.2 (immich-beta.travstats.de)

Additional context

This is not a visibility or feature-flag problem — the component was never written.

The backend is complete:

• backend/src/routes/admin/immich.ts — GET / PUT / POST /test, key masking identical to admin/apiKeys.ts, mounted behind requireAdmin
• admin_settings.global_immich_base_url / global_immich_api_key (migration 20260709120000_immich_albums)
• immichResolver.ts — three-tier resolution: user → admin-global → env

Even the frontend API client already exposes getAdminSettings / updateAdminSettings / testAdminConnection in frontend/src/lib/api/immich.ts — with zero call sites. AdminPage.tsx contains no Immich reference at all.

What is missing is one AdminPage section modelled on GlobalApiKeysManager. Everything below it is already built and tested.

[Abrechen2]

Fixed on the Immich branch and live on the preview. Admin → "Externe Dienste" now contains an instance-wide Immich card — base URL, masked API key and a connection test (verified: "Verbunden · v3.0.2") — so the "provided by administrator" badge finally points at something an admin can actually configure. The former "API keys" section was renamed to "Externe Dienste" in both the admin area and user settings; old bookmarks keep working.

Ships with the Immich release; leaving this open until then.