fix: full patch - reconnect_delay, keepalive, clean_session, QoS1

Patches for paho-mqtt rc=7 at startup (MQTT_ERR_CONN_LOST):

1. reconnect_delay_set(1, 30) - auto-reconnect with backoff
2. keepalive=120 - prevents timeout during long OTP startup
3. subscribe(otp_topic) in on_connect - no race condition
4. time.sleep(0.05) - prevents TCP socket buffer overflow
5. clean_session=False - queued messages survive reconnect
6. qos=1 for discovery configs - PUBACK confirms delivery

src/mqtt.py

@@ -28,7 +28,7 @@ def connect():
     client_id = "volvoAAOS2mqtt" if os.environ.get("IS_HA_ADDON") \
         else "volvoAAOS2mqtt_" + settings.volvoData["username"].replace("+", "")
     try:
-        client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION1, client_id)
+        client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION1, client_id, clean_session=False)
     except AttributeError:
         # paho-mqtt < 2.0 does not have CallbackAPIVersion
         client = mqtt.Client(client_id)
@@ -40,6 +40,7 @@ def connect():
     client.on_message = safe_on_message
     client.on_disconnect = on_disconnect
     client.on_connect = on_connect
+    client.reconnect_delay_set(min_delay=1, max_delay=30)
 
     client.will_set(availability_topic, "offline", 0, False)
     if settings["mqtt"]["username"] and settings["mqtt"]["password"]:
@@ -50,10 +51,9 @@ def connect():
         if isinstance(conf_port, int):
             if conf_port > 0:
                 port = settings["mqtt"]["port"]
-    client.connect(settings["mqtt"]["broker"], port)
+    client.connect(settings["mqtt"]["broker"], port, 120)
     
     client.loop_start()
-    client.subscribe("volvoAAOS2mqtt/otp_code")
 
     global mqtt_client
     mqtt_client = client
@@ -145,6 +145,7 @@ def on_connect(client, userdata, flags, rc):
     logging.info("MQTT connected")
     
     send_heartbeat()
+    mqtt_client.subscribe("volvoAAOS2mqtt/otp_code")
     if len(subscribed_topics) > 0:
         for topic in subscribed_topics:
             mqtt_client.subscribe(topic)
@@ -439,6 +440,7 @@ def update_ha_device(entity, vin, state):
     mqtt_client.publish(
         f"homeassistant/{entity['domain']}/volvoAAOS2mqtt/{vin}_{entity['id']}/config",
         json.dumps(config),
+        qos=1,
         retain=True
     )
 
@@ -489,8 +491,10 @@ def create_ha_devices():
             mqtt_client.publish(
                 f"homeassistant/{entity['domain']}/volvoAAOS2mqtt/{vin}_{entity['id']}/config",
                 json.dumps(config),
+                qos=1,
                 retain=True
             )
+            time.sleep(0.05)
     time.sleep(2)
     send_heartbeat()