[MIRROR] Field of View and Blindness improvements [bounty + upstream push] [MDB IGNORE] (#10060)

* Field of View and Blindness improvements [bounty + upstream push]

* Update death.dm

* almost done

* Update fov_handler.dm

* Face mouse when in combat mode, fix

* Fixes the category for the fov admin verb. #63401

* Fixes objects with bad planes and FoV bugs #63412

* pain

* there we go

* face pref

Co-authored-by: Azarak <azarak10@gmail.com>

code/modules/client/preferences/ambient_occlusion.dm

@@ -5,6 +5,7 @@
 	savefile_identifier = PREFERENCE_PLAYER
 
 /datum/preference/toggle/ambient_occlusion/apply_to_client(client/client, value)
+	/// Backdrop for the game world plane.
 	var/atom/movable/screen/plane_master/game_world/plane_master = locate() in client?.screen
 	if (!plane_master)
 		return

code/modules/client/preferences/fov_darkness.dm

@@ -0,0 +1,17 @@
+/datum/preference/numeric/fov_darkness
+	category = PREFERENCE_CATEGORY_GAME_PREFERENCES
+	savefile_key = "fov_darkness"
+	savefile_identifier = PREFERENCE_PLAYER
+
+	minimum = 0
+	maximum = 255
+
+/datum/preference/numeric/fov_darkness/create_default_value()
+	return 255
+
+/datum/preference/numeric/fov_darkness/apply_to_client_updated(client/client, value)
+	if(client.mob)
+		var/datum/component/fov_handler/fov_component = client.mob.GetComponent(/datum/component/fov_handler)
+		if(!fov_component)
+			return
+		fov_component.visual_shadow.alpha = value