fix: Pulizia topic legacy e discovery retention

- Rimosso vecchio topic homeassistant/sensor/voltronic/config all'avvio
- Aggiunto flag -r (retain) a tutti i discovery topics
- MQTT init eseguito immediatamente all'avvio + ogni 5 minuti
- Aggiunto unique_id e device info a tutti i sensori per HA
- mqtt-subscriber ora ascolta su 3 topic:
  - homeassistant/sensor/voltronic/command (legacy)
  - homeassistant/sensor/voltronic_inv1_raw_cmd/command
  - homeassistant/sensor/voltronic_inv2_raw_cmd/command
- Subscriber con output verbose e timestamp
- Discovery topics ora persistono dopo restart broker MQTT

Timing verificato:
- Init all'avvio: immediato
- Re-init periodico: ogni 5 minuti (300s)
- Data push: ogni 30 secondi

sources/inverter-mqtt/entrypoint.sh

@@ -246,14 +246,32 @@ sleep 2
 MQTT_PUSH_SCRIPT="/opt/inverter-mqtt/mqtt-push-parallel.sh"
 MQTT_INIT_SCRIPT="/opt/inverter-mqtt/mqtt-init-parallel.sh"
 
-# Init the mqtt server for the first time, then every 5 minutes (300 seconds)
+# Remove old single-inverter discovery topics (legacy cleanup)
+echo "Cleaning up legacy MQTT topics..."
+MQTT_SERVER=$(jq -r '.server' /etc/inverter/mqtt.json)
+MQTT_PORT=$(jq -r '.port' /etc/inverter/mqtt.json)
+MQTT_USERNAME=$(jq -r '.username' /etc/inverter/mqtt.json)
+MQTT_PASSWORD=$(jq -r '.password' /etc/inverter/mqtt.json)
+MQTT_DEVICENAME=$(jq -r '.devicename' /etc/inverter/mqtt.json)
+
+mosquitto_pub -h $MQTT_SERVER -p $MQTT_PORT -u "$MQTT_USERNAME" -P "$MQTT_PASSWORD" \
+    -t "$MQTT_TOPIC/sensor/$MQTT_DEVICENAME/config" -n -r > /dev/null 2>&1
+
+echo "✓ Legacy topics cleaned"
+
+# Run MQTT initialization immediately on startup
+echo "Initializing MQTT discovery topics for both inverters..."
+"$MQTT_INIT_SCRIPT"
+echo "✓ MQTT discovery topics initialized"
+
+# Init the mqtt server every 5 minutes (300 seconds)
 # This will re-create the auto-created topics in the MQTT server if HA is restarted...
 echo "Starting MQTT initialization service (every 5 minutes)..."
 watch -n 300 "$MQTT_INIT_SCRIPT" > /dev/null 2>&1 &
 
 # Run the MQTT Subscriber process in the background (so that way we can change the configuration on the inverter from home assistant)
 echo "Starting MQTT subscriber for commands..."
-/opt/inverter-mqtt/mqtt-subscriber.sh &
+/opt/inverter-mqtt/mqtt-subscriber.sh > /dev/null 2>&1 &
 
 # execute exactly every 30 seconds...
 echo "Starting MQTT data push service (every 30 seconds)..."