docs(media): a scan request belongs to the server's own page

Media Relayout.md hit the vault's 500-line gate the moment the tvdb contract
landed, and the fat in it was not the new text: the Plex and Jellyfin scan
blocks (35 lines) sat inside the relayout procedure even though they are the
way you talk to those servers after ANY change, and two Laws bullets repeated
the same facts a third time. Both blocks now live on [[Plex]] and
[[Jellyfin]]; the relayout page keeps the two laws an operator needs at that
moment — 204 is acceptance and anything else queued nothing, and one accepted
refresh is the whole procedure, because a second moves `Scan Media Library` to
`Cancelling` and every later 204 is discarded.

Same pass, the dead numbers the vault's own law says to destroy: an applied
music pass's date, an applied audiobook pass's move/park counts, and the 146
sweep stragglers of one specific first sweep. The laws they taught stay.

490 lines, `bats tests/docs_completeness.bats` 6/6 (length violation gone,
link integrity clean).

serverAppConfigs-docs/Dankserver/Plex.md

@@ -87,3 +87,30 @@ root runs as the `dank` user, and the deployer adopts the data root with
    while the HTTP layer finishes loading; the first boot of a years-old
    library took ~10 minutes (2026-09 cutover). The deployer gate now allows
    600 s before failing; later boots are much faster (warm page cache).
+
+## Triggering a scan
+
+A rename on disk is invisible until the section is rescanned, and a moved file is
+a `Couldn't find the file to stream` 404 until that scan passes it. Run this from
+the host shell through `podman exec`, never from a neighbour container: PMS's
+HTTPD closes without a single byte on any request that arrives from another
+container's netns (10.89.x.x reads as "empty reply", not as a 401). The token
+rides stdin, never argv, where any process on the host could read it out of
+`/proc/<pid>/cmdline`; it lives in `Preferences.xml` inside the RW data bind.
+
+```bash
+umask 077
+podman exec plex sh -c "sed -n 's/.*PlexOnlineToken=\"\\([^\"]*\\)\".*/\\1/p' \
+  '/config/Library/Application Support/Plex Media Server/Preferences.xml'" >/tmp/px.tok
+podman exec -i plex sh -c 'read -r T
+  for k in $(curl -s -H "X-Plex-Token: $T" -H "Accept: application/json" \
+      http://127.0.0.1:32400/library/sections | grep -o "\"key\":\"[0-9]*\"" | cut -d\" -f4); do
+    curl -s -o /dev/null -w "plex section $k: %{http_code}\n" -X POST \
+      -H "X-Plex-Token: $T" "http://127.0.0.1:32400/library/sections/$k/refresh"
+  done' </tmp/px.tok
+```
+
+Every section answers `204` on success. Proof that a rename landed is not a scan
+response — `scripts/media-verify.py` replays the run's journal against the
+database, which is the only read that distinguishes "not scanned yet" from "gone";
+see [[Media Relayout]].