doc 20 covers the multi-layer pin (server / per-user / web SPA / Accept-
Language), the idempotent re-apply runner, drift-check curl one-liners,
known gaps, and a systemd-timer suggestion for weekly auto re-application.
bin/english-lockdown-runner.sh: idempotent runner that POSTs server-wide
UICulture / PreferredMetadataLanguage / MetadataCountryCode and per-user
UICulture / Audio+Subtitle prefs / PlayDefaultAudioTrack. Reads
JELLYFIN_API_TOKEN from env (set -u, refuses to run without it). One-line
summary per surface; exit 0 on full success, 1 on any failure.
doc 15 prefaced with a "Status as of 2026-05-08" section noting the
multi-agent lockdown sweep and cross-linking the audit baseline (doc 19,
sibling) and the new lockdown procedure (doc 20). Original body preserved
verbatim as historical context.