Make lifepo4wered-daemon the primary process in run.sh

The daemon must contact the UPS within PI_BOOT_TO seconds of power-on
or the UPS cuts power. Start it immediately via exec as the container's
main process; run the MQTT monitor in a background loop with 30s restart
backoff so Supervisor API delays or monitor crashes can never delay or
kill the daemon.

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

docs/superpowers/specs/2026-07-18-mqtt-monitor-design.md

@@ -45,10 +45,14 @@ present and one subprocess call reads everything at once.
 
 - Dockerfile: add `python3` + `py3-paho-mqtt` (Alpine packages), copy script
   and `run.sh`, `CMD ["/run.sh"]`.
-- `run.sh` (bashio): pull MQTT host/port/user/password from Supervisor
+- `run.sh` (bashio): `lifepo4wered-daemon -f` is the exec'd main process,
-  services API (works out of the box with the Mosquitto addon), allow
+  started immediately — it must contact the UPS within PI_BOOT_TO seconds of
-  overrides from addon options, start `lifepo4wered-daemon -f` in the
+  power-on or the UPS cuts power, so nothing (Supervisor API calls included)
-  background, run the monitor in the foreground.
+  may delay it and monitor failures must never take it down. The monitor runs
+  in a background subshell that pulls MQTT host/port/user/password from the
+  Supervisor services API (works out of the box with the Mosquitto addon,
+  addon options can override) and restarts the monitor with 30 s backoff if
+  it exits.
 - `config.json`: add `"services": ["mqtt:need"]`, addon options
   (`poll_interval`, optional MQTT overrides), bump version.
 

hassio-addon-lifepo4wered/run.sh

@@ -1,5 +1,11 @@
 #!/usr/bin/with-contenv bashio
 
+# The daemon must contact the UPS within PI_BOOT_TO seconds of power-on,
+# otherwise the UPS assumes the boot failed and cuts power. It is therefore
+# the main process, started before any MQTT/Supervisor API calls, and the
+# monitor runs on the side where its failures can never take the daemon down.
+
+setup_mqtt_env() {
     export POLL_INTERVAL="$(bashio::config 'poll_interval')"
 
     # Manual MQTT settings from addon options win; otherwise use the broker
@@ -25,9 +31,17 @@ else
             "No MQTT broker configured and no mqtt service available;" \
             "trying localhost:1883"
     fi
+}
+
+(
+    setup_mqtt_env
+    bashio::log.info "Starting MQTT monitor (poll interval: ${POLL_INTERVAL}s)"
+    while true; do
+        python3 /usr/bin/lifepo4wered_monitor.py || true
+        bashio::log.warning "MQTT monitor exited; restarting in 30s"
+        sleep 30
+    done
+) &
 
 bashio::log.info "Starting lifepo4wered-daemon"
-lifepo4wered-daemon -f &
+exec lifepo4wered-daemon -f
-
-bashio::log.info "Starting MQTT monitor (poll interval: ${POLL_INTERVAL}s)"
-exec python3 /usr/bin/lifepo4wered_monitor.py