Scale Extra Action Button rim border and hotkey inset with button size

The vanilla border baked into the icon texture grew visible again at
large button sizes since the covering rim used a fixed edge thickness.
Both the rim edge and the hotkey's corner inset now scale with the
button size to keep the border hidden and the hotkey clear of the rim
at any size.

Modules/ExtraActionBar.lua

@@ -20,11 +20,34 @@ local function SkinGlow(button, name)
 	end
 end
 
+local RIM_EDGE_RATIO = 6 / 52 -- 6px confirmed empirically at the native 52px size to fully hide the icon's baked-in vanilla border
+
+local function UpdateRimEdge(button, size)
+	local rim = button and button.CoARim
+	if not rim then return end
+
+	rim:SetBackdrop({edgeFile = E.media.blankTex, edgeSize = size * RIM_EDGE_RATIO})
+	rim:SetBackdropBorderColor(unpack(E.media.bordercolor))
+end
+
+local HOTKEY_MARGIN = 3
+
+local function UpdateHotkeyPosition(button, size)
+	local hotkey = button and _G[button:GetName().."HotKey"]
+	if not hotkey then return end
+
+	local inset = -(size * RIM_EDGE_RATIO + HOTKEY_MARGIN)
+	hotkey:ClearAllPoints()
+	hotkey:Point("TOPRIGHT", inset, inset)
+end
+
 local function UpdateSize(button)
 	button = button or _G[BUTTON_NAME]
 	if button then
 		local size = E.global.CoA.extraActionButtonSize or 52
 		button:SetSize(size, size)
+		UpdateRimEdge(button, size)
+		UpdateHotkeyPosition(button, size)
 	end
 end
 
@@ -100,15 +123,13 @@ local function SkinButton(button, container)
 		local rim = CreateFrame("Frame", nil, button.backdrop)
 		rim:SetAllPoints(icon)
 		rim:SetFrameLevel(button.backdrop:GetFrameLevel() + 10)
-		rim:SetBackdrop({edgeFile = E.media.blankTex, edgeSize = 6})
-		rim:SetBackdropBorderColor(unpack(E.media.bordercolor))
+		button.CoARim = rim
+		UpdateRimEdge(button, E.global.CoA.extraActionButtonSize or 52)
 
 		button:SetFrameLevel(rim:GetFrameLevel() + 1)
 	end
 
 	if hotkey then
-		hotkey:ClearAllPoints()
-		hotkey:Point("TOPRIGHT", -8, -8)
 		hotkey:FontTemplate(LSM:Fetch("font", E.db.actionbar.font), E.db.actionbar.fontSize, E.db.actionbar.fontOutline)
 		hotkey:SetTextColor(1, 1, 1)