docs(audiobookshelf): one page for the endpoint, and the rescan law at the relayout

The page owns the shape, the first-run account step (ABS accepts the initial
account only from a local-network address) and the laws: why the array bind is
read-only and what the one-line rollback is if on-disk sidecars are ever wanted;
why the metadata view is not that rollback; why the mount gate, the wget health
check and the amd64 digest pin are each mandatory; and that LAN-only is a posture,
not an accident.

Media Audiobook Relayout gains the third reader: ABS stores absolute paths, so the
relayout procedure has to reach its library too or it keeps rows for folders that
are gone. The vault index is regenerated, not hand-carved.

serverAppConfigs-docs/Dankserver/Media Audiobook Relayout.md

@@ -11,7 +11,8 @@ timestamp: 2026-10-31T00:00:00Z
 `/mnt/entropy/Audiobooks` is the one library here that [[Jellyfin]] does not read
 at all — its music scanner has no audiobook concept — while [[Plex]] indexes all
 of it as Artist → Album → Track: the album is the BOOK, that book's single artist
-is the NARRATOR, both matched out of the files' own tags. Today one book is split
+is the NARRATOR, both matched out of the files' own tags. [[Audiobookshelf]]
+streams the same tree, read-only, and owns nothing in it. Today one book is split
 across `… [Part 1]`, `… [Part 2]` folders three or four deep inside a collection
 pack, so a scan serves three quarters of a novel; `scripts/media-audiobooks.py`
 re-files the tree so the property both servers' book scanners assume is true —
@@ -36,6 +37,9 @@ python3 scripts/media-audiobooks.py --root /mnt/entropy/Audiobooks \
 #    as [[Media Relayout]] shows, on its own journal, and refresh the Plex section
 #    as in step 5 of the movie Procedure — from inside the container, never over
 #    the host port.
+#    Audiobookshelf stores absolute paths, so the same refresh has to reach its
+#    library too ([[Audiobookshelf]]) — otherwise it keeps rows for folders that
+#    no longer exist.
 scripts/media-apply.py apply --plan /tmp/ab_plan.tsv --root /mnt/entropy \
     --journal /mnt/entropy/media-relayout-audiobooks.jsonl --apply
 ```