Add a Talents skin entry with an enable switch and per-window scale

The talent window, the Vanity and Wardrobe windows it switches between and
the tab row along its bottom are one feature to the player, so they get one
entry in the Skins tree and one master switch gating all three
Initialize calls together. Skinning one of them without the others reads as
a bug.

Scale is a slider per window, 0.5 to 1.5, applied as a multiplier on the
existing scale rather than an absolute -- the three don't ship at the same
size (the vanity store's frame runs about 9% larger than the others), and
that is the server's choice to keep. A setting of 1.0 leaves everything
exactly as it was.

The scale is set on Collections, not on the window itself. All three
windows and the tab row are its children, and it is the only one of them
with mouse enabled -- it is what the player drags. Scaling a window
directly left the drag target at full size, so a shrunk window had to be
grabbed by clicking outside itself, and the tab row, not being a child of
any window, kept whichever size the first-opened one gave it. Scaling the
container moves its hit area with it and the tabs follow as children.

Modules/TalentFrame.lua

@@ -4,8 +4,6 @@ local CoA = E:GetModule("CoA")
 local Skin = CoA.Skin
 
 local FRAME_NAME = "CoATalentFrame"
-local TAB_NAME = "CollectionsPoolFrameCollectionTabTemplate%d"
-local MAX_TABS = 10
 
 -- The talent tree is the one part of the frame we must not touch: every node
 -- is an icon button whose border/overlay textures encode rank and
@@ -595,20 +593,12 @@ local function CropBackground()
 	end
 end
 
--- Tabs go through the shared handler (see Skinning.lua) so they come out
--- identical to the wardrobe's category tabs. The talent frame is passed as the
--- level parent because, unlike those, these tabs aren't its children -- they're
--- separately-placed siblings, so once grown their top edge pokes up behind the
--- frame's own panel art unless they're raised above it.
+-- The tab row is shared with the vanity and wardrobe windows and is handled in
+-- Skinning.lua. The talent frame is passed as its owner while this window is
+-- the open one: the tabs aren't its children, so they don't draw above its
+-- panel on their own.
 local function SkinTabs()
-	local frame = _G[FRAME_NAME]
-
-	for i = 1, MAX_TABS do
-		local tab = _G[TAB_NAME:format(i)]
-		if not tab then break end
-
-		Skin:Tab(tab, frame)
-	end
+	Skin:CollectionTabs(_G[FRAME_NAME])
 end
 
 local SPEC_CHOICE = FRAME_NAME.."SpecViewPoolFrameCoASpecChoiceTemplate%d"
@@ -658,7 +648,8 @@ local function SkinFrame(frame)
 		-- run again on every show rather than once at hook time. The isSkinned
 		-- / backdrop guards inside ElvUI's handlers make re-runs cheap.
 		frame:HookScript("OnShow", function(self)
-			Skin:Title(_G[FRAME_NAME.."TitleText"])
+			Skin:ApplyWindowScale("talentScale")
+	Skin:Title(_G[FRAME_NAME.."TitleText"])
 			SkinCloseButton(self)
 			SkinBottomBar()
 			CropBackground()
@@ -668,6 +659,7 @@ local function SkinFrame(frame)
 		end)
 	end
 
+	Skin:ApplyWindowScale("talentScale")
 	Skin:Title(_G[FRAME_NAME.."TitleText"])
 	SkinCloseButton(frame)
 	SkinBottomBar()