Archived 10.11.z production line (main before the move to 12.1).

main was upstream v10.11.11 plus this fork's fixes: the cyclic ParentId guards,
the OfficialRatingForComparison recursion guard, the AggregateFolder IsRoot fix
and the GitLab CI/Dockerfile for the 10.11 drop-in image. Production ran this
line (ashton/jellyfin:10.11.11, sha256:f804c130...) until it was upgraded to 12.1
on 2026-09-18 (issue #6).

All of those fixes were forward-ported onto 12.1 on upgrade/12.1, which is merged
into main right after this tag. The 10.11 backport notes
(docs/notes/cyclic-parent-backport.md) only live here.