feat: expose scene presets as voice-controllable scene.* entities (0.5.0)

Add a SCENE platform (scene.py) so each scene preset becomes a scene.*
entity. Alexa / Google Assistant / HomeKit expose the scene, light, and
switch domains — but NOT button — so the existing button.* scene entities
are invisible to voice assistants. Scenes use a distinct unique_id so both
coexist (buttons for dashboards, scenes for voice).

- Register Platform.SCENE; bump manifest 0.4.0 -> 0.5.0
- README: "Voice Control (Alexa / Google / Siri)" guide (Nabu Casa cloud,
  manual skill linking, HomeKit bridge, voice-friendly naming)

custom_components/ledgrab/__init__.py

@@ -31,6 +31,7 @@ _LOGGER = logging.getLogger(__name__)
 PLATFORMS: list[Platform] = [
     Platform.BUTTON,
     Platform.LIGHT,
+    Platform.SCENE,
     Platform.SWITCH,
     Platform.SENSOR,
     Platform.NUMBER,

custom_components/ledgrab/manifest.json

@@ -8,5 +8,5 @@
   "iot_class": "local_push",
   "issue_tracker": "https://git.dolgolyov-family.by/alexei.dolgolyov/ledgrab-haos-integration/issues",
   "requirements": ["aiohttp>=3.9.0"],
-  "version": "0.4.0"
+  "version": "0.5.0"
 }

custom_components/ledgrab/scene.py

@@ -0,0 +1,81 @@
+"""Scene platform for LedGrab — scene presets as voice-activatable scenes.
+
+Scene presets are also exposed as ``button.*`` entities (see button.py) for
+dashboard use. Buttons, however, are NOT in the set of entity domains that
+Alexa / Google Assistant / HomeKit expose to voice assistants — ``scene.*`` is.
+This platform adds a ``scene.*`` entity per preset so "Alexa, turn on Movie
+Night" works, while leaving the buttons in place for existing dashboards.
+"""
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+from homeassistant.components.scene import Scene
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers.entity_platform import AddEntitiesCallback
+from homeassistant.helpers.update_coordinator import CoordinatorEntity
+
+from .const import DOMAIN, DATA_COORDINATOR
+from .coordinator import LedGrabCoordinator
+
+_LOGGER = logging.getLogger(__name__)
+
+
+async def async_setup_entry(
+    hass: HomeAssistant,
+    entry: ConfigEntry,
+    async_add_entities: AddEntitiesCallback,
+) -> None:
+    """Set up a scene entity per scene preset."""
+    data = hass.data[DOMAIN][entry.entry_id]
+    coordinator: LedGrabCoordinator = data[DATA_COORDINATOR]
+
+    entities: list[Scene] = []
+    if coordinator.data:
+        for preset in coordinator.data.get("scene_presets", []):
+            entities.append(LedGrabScene(coordinator, preset, entry.entry_id))
+
+    async_add_entities(entities)
+
+
+class LedGrabScene(CoordinatorEntity, Scene):
+    """A scene preset exposed as a HA scene (voice-friendly)."""
+
+    # Full standalone name so utterances like "turn on Movie Night" match,
+    # instead of the "<device> <entity>" composite that has_entity_name gives.
+    _attr_has_entity_name = False
+    _attr_icon = "mdi:palette"
+
+    def __init__(
+        self,
+        coordinator: LedGrabCoordinator,
+        preset: dict[str, Any],
+        entry_id: str,
+    ) -> None:
+        """Initialize the scene."""
+        super().__init__(coordinator)
+        self._preset_id = preset["id"]
+        self._entry_id = entry_id
+        # Distinct from the button's unique_id so both can coexist.
+        self._attr_unique_id = f"{entry_id}_scene_entity_{preset['id']}"
+        self._attr_name = preset["name"]
+
+    @property
+    def device_info(self) -> dict[str, Any]:
+        """All scene entities belong to the same Scenes device as the buttons."""
+        return {"identifiers": {(DOMAIN, f"{self._entry_id}_scenes")}}
+
+    @property
+    def available(self) -> bool:
+        """Return if the underlying preset still exists."""
+        if not self.coordinator.data:
+            return False
+        return self._preset_id in {
+            p["id"] for p in self.coordinator.data.get("scene_presets", [])
+        }
+
+    async def async_activate(self, **kwargs: Any) -> None:
+        """Activate the scene preset."""
+        await self.coordinator.activate_scene(self._preset_id)