feat(displays): per-display devices + DDC/CI capability entities

Restructure how displays are exposed in Home Assistant:

Each physical monitor is now its own HA device linked to the media-server
hub via `via_device`. The hub keeps the media_player + script buttons; per-
display devices hold the power switch, brightness slider, and the new
capability entities. This lets users place displays in their own area/room
and keeps related entities grouped together in the UI.

New platforms:
- sensor: DisplayResolutionSensor (diagnostic, from EDID)
- binary_sensor: DisplayPrimaryBinarySensor + DisplayPowerControlBinarySensor
  (both diagnostic; help users see why a power switch is or isn't created)
- select: DisplayInputSourceSelect (HDMI1/DP1/...), DisplayColorPresetSelect
  (color temperature), DisplayPictureModeSelect (VCP 0xDC scene modes)
- number: added DisplayContrastNumber alongside brightness

Other changes:
- display_device helper centralises the per-display DeviceInfo; pulls real
  manufacturer/model from EDID; device name no longer prepends the hub
  title since via_device already shows the hierarchy.
- api_client gains set_display_{contrast,input_source,color_preset,picture_mode}
  and stops forcing `?refresh=true` on every poll so HA can ride the
  server's TTL cache instead of triggering full DDC/CI probes per entity.
- select / number entities now check the server's `success` flag and re-
  sync from the actual monitor state when a write was silently rejected
  (some monitors honor reads but ignore writes for certain DDC/CI codes).

Bumps manifest.json to 0.3.0 - the device topology change is user-visible
and existing brightness/power entities migrate to per-display devices on
first reload (unique_ids are preserved).

custom_components/remote_media_player/__init__.py

@@ -27,7 +27,15 @@ from .const import (
 
 _LOGGER = logging.getLogger(__name__)
 
-PLATFORMS: list[Platform] = [Platform.MEDIA_PLAYER, Platform.BUTTON, Platform.NUMBER, Platform.SWITCH]
+PLATFORMS: list[Platform] = [
+    Platform.MEDIA_PLAYER,
+    Platform.BUTTON,
+    Platform.NUMBER,
+    Platform.SWITCH,
+    Platform.SENSOR,
+    Platform.BINARY_SENSOR,
+    Platform.SELECT,
+]
 
 # Service schema for execute_script
 SERVICE_EXECUTE_SCRIPT_SCHEMA = vol.Schema(