Skin the Apply and Cancel buttons on the wardrobe model

Both only exist while a transmog change is pending, which is why every
earlier pass over the frame missed them -- it was always skinned in its idle
state -- so they still wore their native green and red pills against an
otherwise flat window.

They are the same widget as the specialization menu's Activate button: no
Normal/Pushed texture for HandleButton to clear, the pill drawn across plain
regions from an atlas. Two files, not one -- Apply takes the green variant of
128GoldRedButton, Cancel is drawn from 128RedButton, HIGHLIGHT region and all,
which is what left a red glow under the cursor once only the gold file was
being cleared. The shared "RedButton" suffix matches both. Their labels take
ElvUI's yellow rather than carrying the atlas's green/red split over: the two
sit side by side and read apart by their text.

The buttons exist from the start rather than being created on the first
pending change, so the normal skin pass reaches them, but the art is only
there to be cleared once a change is pending -- and nothing fires the frame's
OnShow at that point, since the window is already open. The buttons' own
OnShow catches it instead.

The clear-by-file loop the Activate button and the dropdown pills had a copy
of each now lives in Skinning.lua as Skin:StripArtByFile, with the atlas name
alongside it.

Modules/WardrobeFrame.lua

@@ -13,6 +13,54 @@ local function SkinActionButtons()
 	S:HandleButton(_G[FRAME_NAME.."DisableSpellVisualsButton"])
 end
 
+-- Apply and Cancel only exist while a transmog change is pending, which is why
+-- they were missed for so long -- but they exist from the start rather than
+-- being created on the first change (probed: both are Buttons, hidden, with
+-- nothing pending), so the normal skin pass reaches them.
+--
+-- Same widget as the talent frame's Activate button: the pill is drawn across
+-- plain regions, with no Normal/Pushed texture for HandleButton to clear
+-- (probed: both come back nil). Apply takes the green variant of the gold
+-- atlas, Cancel is drawn from the red file instead -- Skin.RedButtonArt matches
+-- both, and Cancel's HIGHLIGHT region goes with the rest of its art.
+--
+-- The labels don't carry the atlas's green/red split over: the two buttons sit
+-- side by side and read apart by their text, and they take the same yellow
+-- every other templated button on these frames uses -- the talent frame's live
+-- Activate label included -- so a pending change doesn't get its own colour
+-- scheme.
+local LABEL_COLOR = {1, 0.82, 0}
+
+-- The strip runs on every pass rather than once behind the skinned guard: the
+-- art is only there to be cleared once a change is pending, and nothing fires
+-- the frame's OnShow at that point -- the window is already open. The buttons'
+-- own OnShow is what catches it, since that is exactly when they appear.
+local function SkinPendingButton(name)
+	local button = _G[name]
+	if not button then return end
+
+	Skin:StripArtByFile(button, Skin.RedButtonArt)
+
+	if button.CoASkinned then return end
+	button.CoASkinned = true
+
+	-- Stripped before templating: HandleButton adds its backdrop as regions of
+	-- this same button, so a strip afterwards takes the backdrop with the pill.
+	S:HandleButton(button)
+
+	local text = button.GetFontString and button:GetFontString()
+	if text then text:SetTextColor(unpack(LABEL_COLOR)) end
+
+	button:HookScript("OnShow", function(self)
+		Skin:StripArtByFile(self, Skin.RedButtonArt)
+	end)
+end
+
+local function SkinPendingButtons()
+	SkinPendingButton(FRAME_NAME.."PlayerModelApplyButton")
+	SkinPendingButton(FRAME_NAME.."PlayerModelCancelButton")
+end
+
 local function SkinSearchBox()
 	S:HandleEditBox(_G[FRAME_NAME.."CollectionSearchBox"])
 end
@@ -59,6 +107,7 @@ local function SkinContents()
 	Skin:Title(_G[FRAME_NAME.."TitleText"])
 	Skin:CloseButton(_G[FRAME_NAME.."CloseButton"])
 	SkinActionButtons()
+	SkinPendingButtons()
 	SkinSearchBox()
 	SkinCollectionDropdown("Filter")
 	SkinCollectionDropdown("Sorting")