feat: initial release — LedGrab Home Assistant integration

HACS-compatible custom component split out from the main LedGrab repo.
Creates light, switch, sensor, number, and select entities for each
configured LedGrab device.

custom_components/ledgrab/services.yaml

@@ -0,0 +1,19 @@
+set_leds:
+  name: Set LEDs
+  description: Push segment data to an api_input color strip source
+  fields:
+    source_id:
+      name: Source ID
+      description: The api_input CSS source ID (e.g., css_abc12345)
+      required: true
+      selector:
+        text:
+    segments:
+      name: Segments
+      description: >
+        List of segment objects. Each segment has: start (int), length (int),
+        mode ("solid"/"per_pixel"/"gradient"), color ([R,G,B] for solid),
+        colors ([[R,G,B],...] for per_pixel/gradient)
+      required: true
+      selector:
+        object: