Add CoAClassColors.lua: mirror RAID_CLASS_COLORS into CUSTOM_CLASS_COLORS

Kui_Nameplates picks its colour source table once at load
(Modules/ClassColours.lua:90 and Libs/Kui/Kui.lua:56-60):

    cc_table = CUSTOM_CLASS_COLORS or RAID_CLASS_COLORS

with no per-key fallback. When the !ClassColors addon is loaded it
injects a vanilla-10-only CUSTOM_CLASS_COLORS, so the 22 CoA tokens
silently fall through and class-coloured friendly names disappear
(plus a nil-arg in kui.GetClassColour for the str path).

New file mirrors any RAID_CLASS_COLORS entry that CUSTOM_CLASS_COLORS
is missing, when !ClassColors is loaded. Idempotent — only fills nil
keys, so user customisations win. RAID_CLASS_COLORS itself is left
untouched (the Voljin/CoA client populates it from
patch-B.MPQ → SharedXML/SharedConstants.lua).

Same pattern as coa-omen and coa-shadowedunitframes' fixes.

Kui_Nameplates/CoAClassColors.lua

@@ -0,0 +1,74 @@
+-- CoAClassColors.lua
+--
+-- Forwards the live client's RAID_CLASS_COLORS palette into
+-- _G.CUSTOM_CLASS_COLORS so Kui_Nameplates renders Conquest-of-Azeroth
+-- class names and bars correctly when the !ClassColors addon is
+-- loaded.
+--
+-- Background
+-- ----------
+-- The CoA Voljin client (and the Ascension classic+ client) ship
+-- Interface/SharedXML/SharedConstants.lua with all 32 class
+-- file_strings populated in _G.RAID_CLASS_COLORS — 10 vanilla + HERO +
+-- 21 CoA customs (BARBARIAN, WITCHDOCTOR, DEMONHUNTER, FLESHWARDEN,
+-- MONK = Templar, PROPHET = Venomancer, …).
+--
+-- Kui_Nameplates picks its source table once in
+-- Modules/ClassColours.lua:90 with
+--     cc_table = CUSTOM_CLASS_COLORS or RAID_CLASS_COLORS
+-- and Libs/Kui/Kui.lua:56-60 has the same shape:
+--     if CUSTOM_CLASS_COLORS then class = CUSTOM_CLASS_COLORS[class]
+--     else                         class = RAID_CLASS_COLORS[class]
+--     end
+-- When !ClassColors is loaded it injects a separate
+-- _G.CUSTOM_CLASS_COLORS populated from its own (vanilla-10-only)
+-- defaults plus user overrides. There is *no* per-key fallback to
+-- RAID_CLASS_COLORS, so on a !ClassColors-equipped client the 22 CoA
+-- tokens silently miss and SetTextColor is called with a nil colour
+-- (no class-coloured friendly names; nil-arg error in
+-- kui.GetClassColour for the str path).
+--
+-- Strategy
+-- --------
+-- If CUSTOM_CLASS_COLORS exists at file-load time (i.e. !ClassColors
+-- already loaded — Kui_Nameplates.toc declares it as an OptionalDep,
+-- so it loads first when installed), copy any RAID_CLASS_COLORS entry
+-- that CUSTOM_CLASS_COLORS is missing. Never overwrite —
+-- !ClassColors user preferences and any other addon's earlier write
+-- win.
+--
+-- We deliberately don't touch RAID_CLASS_COLORS itself: the client
+-- already populates it, and any value we'd choose here would be a
+-- guess relative to the realm-authoritative palette in
+-- SharedConstants.lua.
+--
+-- Source of truth: _G.RAID_CLASS_COLORS at FrameXML load time
+-- (Voljin/PTR realm: patch-B.MPQ → SharedXML/SharedConstants.lua).
+
+local CCC = _G.CUSTOM_CLASS_COLORS
+if type(CCC) ~= "table" then return end
+
+local CC = _G.RAID_CLASS_COLORS
+if type(CC) ~= "table" then return end
+
+local function colorStr(r, g, b)
+	return string.format("ff%02x%02x%02x", r * 255 + 0.5, g * 255 + 0.5, b * 255 + 0.5)
+end
+
+local function unpackColor(c)
+	if type(c) ~= "table" then return end
+	if c.GetRGB then return c:GetRGB() end
+	return c.r, c.g, c.b
+end
+
+for token, src in pairs(CC) do
+	if CCC[token] == nil then
+		local r, g, b = unpackColor(src)
+		if r and g and b then
+			CCC[token] = {
+				r = r, g = g, b = b,
+				colorStr = colorStr(r, g, b),
+			}
+		end
+	end
+end

Kui_Nameplates/Kui_Nameplates.toc

@@ -3,6 +3,7 @@
 ## Title: Kui |cff9966ffNameplates|r
 ## Version: 263
 ## Notes: Prettier nameplates.
+## OptionalDeps: !ClassColors
 ## SavedVariables: KuiNameplatesGDB
 ## X-Curse-Packaged-Version: 262
 ## X-Curse-Project-Name: KuiNameplates
@@ -13,5 +14,13 @@
 
 Embeds.xml
 Locales.xml
+
+## CoA patches ##
+# Mirror RAID_CLASS_COLORS into CUSTOM_CLASS_COLORS for the 22 CoA
+# class tokens before any module captures cc_table. Loaded after
+# Embeds (defensive — this file uses no libs) and before Core/Modules
+# so ClassColours.lua:90 sees the populated CCC at OnInitialize time.
+CoAClassColors.lua
+
 Core.xml
 Modules.xml