Use HassKey in core components (a-c) (#126258)

* Use HassKey in conversation

* Use HassKey in assist_satellite

* automation

* More

* Unrelated

* Improve

homeassistant/components/camera/const.py

@@ -1,8 +1,10 @@
 """Constants for Camera component."""
 
+from __future__ import annotations
+
 from enum import StrEnum
 from functools import partial
-from typing import Final
+from typing import TYPE_CHECKING, Final
 
 from homeassistant.helpers.deprecation import (
     DeprecatedConstantEnum,
@@ -10,8 +12,15 @@ from homeassistant.helpers.deprecation import (
     check_if_deprecated_constant,
     dir_with_deprecated_constants,
 )
+from homeassistant.util.hass_dict import HassKey
+
+if TYPE_CHECKING:
+    from homeassistant.helpers.entity_component import EntityComponent
+
+    from . import Camera
 
 DOMAIN: Final = "camera"
+DOMAIN_DATA: HassKey[EntityComponent[Camera]] = HassKey(DOMAIN)
 
 DATA_CAMERA_PREFS: Final = "camera_prefs"
 DATA_RTSP_TO_WEB_RTC: Final = "rtsp_to_web_rtc"