zwave-js-ui: mount only the settings file, not the config directory

":Z" relabels what it mounts to container_file_t, recursively and on disk, and
init.sh lives in /etc/quadlets/zwave-js-ui. Mounting that directory into the
container therefore left a script systemd could no longer execute:
zwave-js-ui-init.service failed with 203/EXEC at every boot after the first
start of the container, and the container's Requires= on it kept the container
down too. A machine that survived its installation stopped surviving a reboot.

Found on the target machine, not in review: the first installation works,
because Ignition writes /etc with the right labels and the init service runs
before the container. The fault only appears at the second boot.

The README also gains a "Clearing the store" section. The seed is a first-boot
mechanism, so an operator who deletes settings.json -- after rotating the
security keys, for instance, since Z-Wave JS UI keeps its own copy of the old
ones -- has to restart the init service explicitly. "systemctl restart
zwave-js-ui.target" does not re-run it: it is RemainAfterExit=yes and already
active. Getting that wrong leaves a container unhealthy forever with a happy
driver, and authentication silently off.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

cookbooks/zwave-js-ui/README.md

@@ -198,8 +198,40 @@ a restart loop fixes.
   artifact. What the external file buys is not secrecy: it is that the authoritative copy lives
   outside the application, is restorable from a vault, and cannot be edited from the web
   interface.
+- **Only `external-settings.json` is mounted into the container, never the configuration
+  directory.** `:Z` relabels what it mounts to `container_file_t`, recursively and on disk, and
+  `init.sh` lives in that directory. Mounting the directory therefore leaves a script systemd
+  can no longer execute: `zwave-js-ui-init.service` fails with `203/EXEC` at every boot *after
+  the first start of the container*, and the container's `Requires=` on it keeps the container
+  down too. A machine that survived its installation stops surviving a reboot, which is the
+  worst shape a fault can take. The `mosquitto` cookbook mounts its whole directory and is fine
+  because it keeps no script there; this one does.
 - **No Traefik and no TLS.** See "What this cookbook does NOT do".
 
+## Clearing the store
+
+The seed is a **first-boot** mechanism: `init.sh` writes `store/settings.json` only when it is
+absent, because Z-Wave JS UI owns that file afterwards. Two consequences for an operator who
+wipes the store, or who deletes `settings.json` to force the settings of
+`external-settings.json` back in — after rotating the security keys, for instance, since
+Z-Wave JS UI keeps its own copy of the old ones:
+
+- **Delete the file with the container stopped, then restart the init service explicitly**, in
+  this order. `systemctl restart zwave-js-ui.target` is not enough: the init service is
+  `RemainAfterExit=yes` and already active, so it does not run again, and Z-Wave JS UI then
+  writes a `settings.json` that holds the external settings and **not** the seeded ones.
+- The symptom of getting it wrong is a container that is `unhealthy` forever with a driver that
+  is perfectly happy: no `mqtt` section means no MQTT client, and `/health` answers 500. And,
+  more quietly, `gateway.authEnabled` is gone with it, so the web interface stops asking for a
+  password.
+
+```sh
+systemctl stop zwave-js-ui.service
+rm /var/lib/virtiofs/data/zwave-js-ui/settings.json
+systemctl restart zwave-js-ui-init.service     # seeds it again
+systemctl start zwave-js-ui.service
+```
+
 ## Usage
 
 In a separate terminal, follow the logs.

cookbooks/zwave-js-ui/zwave-js-ui.container

@@ -59,9 +59,19 @@ Environment=STORE_DIR=/var/lib/virtiofs/data/zwave-js-ui
 # SESSION_SECRET and the initial administrator credentials (site secrets).
 EnvironmentFile=/etc/quadlets/zwave-js-ui/zwave-js-ui.env
 
-# Configuration (read-only), at the same path inside and outside the container so
-# that ZWAVE_EXTERNAL_SETTINGS names one path only.
-Volume=/etc/quadlets/zwave-js-ui:/etc/quadlets/zwave-js-ui:ro,Z
+# Configuration (read-only): the ONE file the container reads, at the same path
+# inside and outside so that ZWAVE_EXTERNAL_SETTINGS names one path only.
+#
+# Never mount the whole /etc/quadlets/zwave-js-ui directory here. ":Z" relabels
+# what it mounts to container_file_t, recursively and on disk, and init.sh lives
+# in that directory: systemd can no longer execute it, so
+# zwave-js-ui-init.service fails 203/EXEC at every boot after the first start of
+# this container, and the Requires= above then keeps the container down with it.
+# A machine that survived its install stops surviving a reboot.
+#
+# ConditionPathExists on this file above is also what keeps podman from creating
+# a DIRECTORY at this path when the operator has not provided the file.
+Volume=/etc/quadlets/zwave-js-ui/external-settings.json:/etc/quadlets/zwave-js-ui/external-settings.json:ro,Z
 
 # Precious data: the store holds the node names, the associations, the NVM
 # backups of the controller and the users of the web interface. It lives on the