docs(media): one page for the metadata view, and the three pages it re-points

New owner page Dankserver/Media Metadata View.md: the shape, the two binds and
why Plex keeps the /mnt/entropy container path, the commands, the laws (SSD-only
upper layer, never mount over an unmounted array, never delete through the view
because a whiteout only hides the array's copy, reap after any relayout, inotify
does not cross the merge), the failure signatures, and the rollback.

Jellyfin.md: /data is the view, so Local metadata works; the
"Read-only file system : '/data/…/movie.nfo'" line that used to be expected noise
is now the signature of a missing view. Plex.md: same bind, one fact changed.
Media Relayout.md: two new laws for the metadata that does not follow a rename.
AGENTS.md: runbook-index row plus a summary row. Root index regenerated.

serverAppConfigs-docs/Dankserver/Jellyfin.md

@@ -1,9 +1,9 @@
 ---
 type: reference
 title: Jellyfin
-description: "Jellyfin on Dankserver: quadlet unit, entropy-volume data layout, ports, client access, hardware-transcode status."
+description: "Jellyfin on Dankserver: quadlet unit, overlay metadata view layout, ports, access, hardware-transcode status."
 tags: [jellyfin, dankserver, media-server]
-timestamp: 2026-09-03T00:00:00Z
+timestamp: 2026-10-30T00:00:00Z
 ---
 
 # Jellyfin
@@ -26,7 +26,7 @@ public vhost `jelly.franksdank.cloud` behind the [[Anubis]] guard chain →
 | Image | `ghcr.io/jellyfin/jellyfin:latest` |
 | Network | `dankserver_appnet`; publishes 8096/tcp, 8920/tcp, 7359/udp, 1900/udp |
 | Data roots | `/home/dank/Containers/jellyfin/config:/config`, `/home/dank/Containers/jellyfin/cache:/cache` |
-| Media | `Volume=/mnt/entropy:/data:ro` — the whole [[Entropy Volume]] mounted read-only; nothing automated writes to it |
+| Media | `Volume=/mnt/media:/data` — the [[Media Metadata View]] overlay, **writable**; sidecars land on the NVMe, the [[Entropy Volume]] array underneath stays read-only and untouched |
 | GPU | none — no `AddDevice`; CPU decode only (jellyfin-ffmpeg path) |
 | Env quirks | `DOTNET_SYSTEM_IO_DISABLEFILELOCKING=true`, `LD_PRELOAD=libjemalloc.so.2`, `MALLOC_TRIM_THRESHOLD_=131072` kept verbatim from the compose-era container (zero-drift cutover) |
 | Health | `curl -f http://localhost:8096/health` every 30 s |
@@ -36,20 +36,23 @@ public vhost `jelly.franksdank.cloud` behind the [[Anubis]] guard chain →
 ```
 /home/dank/Containers/jellyfin/config   -> /config   (JELLYFIN_DATA_DIR)
 /home/dank/Containers/jellyfin/cache    -> /cache    (JELLYFIN_CACHE_DIR, XDG_CACHE_HOME)
-/mnt/entropy                            -> /data     (read-only media volume)
+/mnt/media                             -> /data     (the SSD-backed overlay view)
 ```
 
-Library folders point at `/data` paths; because the mount uses the same
-absolute path as on the host, library paths survive container recreation.
+Library folders point at `/data` paths, which are the view's paths: stable
+across container recreation, and identical to the raw array layout below it.
 
-`Local metadata` — save metadata to media folders — cannot work against a `ro`
-mount, and it is enabled: every item update logs
-`System.IO.IOException: Read-only file system : '/data/Movies/<film>/movie.nfo'`.
-The exception lands in the sidecar saver, after the database row is written, so
-indexing proceeds anyway — a 2026-10-30 scan dropped stale records and added
-episodes while these lines filled the log. Expected noise, not a fault: if it
-ever needs silencing, turn the saver off under *Library → Metadata* rather than
-making `/data` writable.
+`Local metadata` — save metadata to media folders — is enabled, and it works
+because `/data` is the [[Media Metadata View]] rather than the read-only array:
+`movie.nfo`, `tvshow.nfo`, `episode.nfo` and artwork are written once, on the
+NVMe upper layer, and [[Plex]] reads the same files. Jellyfin is the fleet's
+only metadata writer.
+
+**Failure signature:** `System.IO.IOException: Read-only file system :
+'/data/Movies/<film>/movie.nfo'` means the container is binding the raw array
+instead of the view — the view is unmounted or the quadlet drifted. That used to
+be the expected state (pre-view, every item update logged it); today it is a
+fault. Run `scripts/media-view.sh status`.
 
 ## Ports & access