Expose device brightness as HA number entity

Add a Number platform to the HAOS integration so each LED target
with a brightness-capable device gets a 0-255 slider in Home
Assistant. Coordinator now fetches device list and brightness on
each poll cycle. Also enable chart animation in perf-charts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

custom_components/wled_screen_controller/__init__.py

@@ -29,6 +29,7 @@ _LOGGER = logging.getLogger(__name__)
 PLATFORMS: list[Platform] = [
     Platform.SWITCH,
     Platform.SENSOR,
+    Platform.NUMBER,
 ]