User admin in the web UI, admin-only log, unread-first OPML feeds

- Settings > Manage users: add an account (password, or none for proxy
  sign-in), toggle admin, remove. Backed by GET/POST /api/users and
  PATCH/DELETE /api/users/{id}, 403 for non-admins. The only admin
  cannot be demoted or removed.
- GET /api/logs is admin-only and the Log button is hidden for others;
  the log names every account, feed and failed sign-in.
- Feeds inside an OPML list those with unread items first, in the
  sidebar folder and on the subscription's page.
- Deploying is now buildx --push to 192.168.1.130:5000 and recreating
  the ipodderx service of the Arcane project content; CLAUDE.md and the
  README's Docker section say so.
- Tests: Playwright for user admin, the last-admin guard, 403s for a
  non-admin and the unread ordering (new Aardvark Radio fixture); a unit
  test for last_admin; the smoke test drives usersModal.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0173mGu6rK18Ne7UGTwAaVJV

docs/architecture.md

@@ -110,8 +110,9 @@ else a `401`.
 | `POST /api/enclosures/{id}/download`, `DELETE /api/enclosures/{id}` | `?force=true` overrides the shared-file warning |
 | `POST /api/fetch`, `GET /api/opml`, `POST /api/opml` | |
 | `GET /api/settings`, `PATCH /api/settings` | admin-only to write |
+| `GET /api/users`, `POST /api/users`, `PATCH /api/users/{id}`, `DELETE /api/users/{id}` | admin-only; the only admin cannot be demoted or removed |
 | `GET /api/events` | SSE, the same broadcast the socket carries |
-| `GET /api/logs` | the ring buffer, with a sequence cursor |
+| `GET /api/logs` | admin-only; the ring buffer, with a sequence cursor |
 | `GET /media/{id}` | the file, with Range support so seeking works |
 
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