ensure_bind_mount_dirs chowned a freshly-created no-data_uid bind dir
with --reference={immediate_parent}. For a NESTED bind source like
jellyfin's /var/lib/archipelago/jellyfin/config (or netbird's .../netbird/
data), `mkdir -p` creates the intermediate <app> dir root:root too, so
referencing the immediate parent just copied ROOT — leaving the dir
unwritable and the app EACCES-crash-looping on reinstall (found by the
all-apps-lifecycle pass: jellyfin "/config/log denied" exit 139;
netbird-server "unable to open database file"). It only ever worked for
direct children of the data root (immich).
Fix: anchor to the nearest PRE-EXISTING ancestor (the rootless data root,
owned by the service user) and chown -R the entire newly-created subtree
to it. Extracted the walk into fresh_subtree_anchor() with a unit test
covering nested / direct / second-volume cases.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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