Add GPS extra state attributes to device_tracker

Expose altitude, course, and speed as extra_state_attributes on the
device_tracker entity. Refactor to use _update_from_location for
consistent attribute updates on init and on_update.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: tomer-w

custom_components/victron_mqtt/device_tracker.py

@@ -15,12 +15,17 @@
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers.device_registry import DeviceInfo
 from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
+from homeassistant.helpers.typing import StateType
 
 from .entity import VictronBaseEntity
 from .hub import VictronGxConfigEntry
 
 PARALLEL_UPDATES = 0
 
+ATTR_ALTITUDE = "altitude"
+ATTR_COURSE = "course"
+ATTR_SPEED = "speed"
+
 
 async def async_setup_entry(
     hass: HomeAssistant,
@@ -58,14 +63,31 @@ def __init__(
         installation_id: str,
     ) -> None:
         """Initialize the device tracker."""
-        super().__init__(device, metric, device_info, "device_tracker",  simple_naming, installation_id)
-        if isinstance(metric.value, GpsLocation):
-            self._attr_latitude = metric.value.latitude
-            self._attr_longitude = metric.value.longitude
+        super().__init__(device, metric, device_info, "device_tracker", simple_naming, installation_id)
+        self._update_from_location(metric.value)
 
     @callback
     def _on_update_cb(self, value: Any) -> None:
+        self._update_from_location(value)
+        self.async_write_ha_state()
+
+    def _update_from_location(self, value: Any) -> None:
+        """Update entity attributes from a GpsLocation value."""
         if isinstance(value, GpsLocation):
             self._attr_latitude = value.latitude
             self._attr_longitude = value.longitude
-            self.async_write_ha_state()
+            self._altitude = value.altitude
+            self._course = value.course
+            self._speed = value.speed
+
+    @property
+    def extra_state_attributes(self) -> dict[str, StateType]:
+        """Return extra state attributes for altitude, course, and speed."""
+        attrs: dict[str, StateType] = {}
+        if self._altitude is not None:
+            attrs[ATTR_ALTITUDE] = self._altitude
+        if self._course is not None:
+            attrs[ATTR_COURSE] = self._course
+        if self._speed is not None:
+            attrs[ATTR_SPEED] = self._speed
+        return attrs