feat(tracker): add objective marker button to quest lines

Ascension's client backports retail's floating objective marker. This adds
a button to each tracker quest line that points the marker at that quest,
mirroring the quest pin the world map draws for it.

Supertracking is a slave of the map's quest selection: both the map and the
Blizzard watch frame funnel through SelectQuestLogEntry, and calling
C_SuperTrack.SetSuperTrackedQuestID directly only moves the marker until the
next map interaction stomps it. So the button clicks the same POI frame the
client clicks -- the watch frame button when one exists, otherwise the map's
quest frame.

The client dropped GetSuperTrackedQuestID, so the current quest is read by
hooking SetSuperTrackedQuestID instead. Every path ends up there, including
the automatic re-pick on zone change, so the highlight cannot fall out of
sync with tracking changed outside the addon. Caching what we last set would
have gone stale the moment the player used the map.

The button mirrors the pin's own textures rather than picking atlas cells, so
the digit, the "?" completed quests use and the selected variant all follow
whatever the client draws. Quests with no pin get no button, and the map's
POI frames are built on demand so buttons appear without opening the map.

Adds trackerShowSuperTrackButton and trackerSuperTrackButtonSize.

Modules/Tracker/TrackerUtils.lua

@@ -1265,6 +1265,158 @@ function TrackerUtils:GetSortedQuestIds()
     return sortedQuestIds, questDetails
 end
 
+-- Ascension's 3.3.5 client backports the retail floating objective marker ("SuperTracker").
+-- Supertracking is a slave of the quest log selection: the world map and the Blizzard watch frame
+-- both funnel through SelectQuestLogEntry -> SuperTrackerUtil.SetToBestSuperTrackingType. Calling
+-- C_SuperTrack.SetSuperTrackedQuestID directly only moves the marker until the next map interaction
+-- stomps it, so we click the same POI frames the client itself clicks.
+local superTrackedQuestId
+local superTrackHooked
+
+function TrackerUtils:IsSuperTrackAvailable()
+    return (C_SuperTrack ~= nil) and ((WorldMapFrame_SelectQuestFrame ~= nil) or (WatchFrameQuestPOI_OnClick ~= nil))
+end
+
+-- Every path that changes the supertracked quest ends up in SetSuperTrackedQuestID -- our own
+-- button, world map pins, the map quest list, the Blizzard tracker, and the automatic re-pick that
+-- happens when the map switches zone. Hooking it is the only way to know what is supertracked,
+-- since this client dropped the GetSuperTrackedQuestID getter. Caching what we last set would go
+-- stale the moment the player changed it by any other means.
+function TrackerUtils:InitSuperTrackHook()
+    if superTrackHooked or (not C_SuperTrack) then
+        return
+    end
+
+    superTrackHooked = true
+
+    hooksecurefunc(C_SuperTrack, "SetSuperTrackedQuestID", function(questId)
+        superTrackedQuestId = questId
+        TrackerLinePool.UpdateSuperTrackButtons()
+    end)
+
+    if C_SuperTrack.ClearSuperTracker then
+        hooksecurefunc(C_SuperTrack, "ClearSuperTracker", function()
+            superTrackedQuestId = nil
+            TrackerLinePool.UpdateSuperTrackButtons()
+        end)
+    end
+end
+
+function TrackerUtils:GetSuperTrackedQuestId()
+    return superTrackedQuestId
+end
+
+-- The world map builds its quest POI frames lazily, so right after login -- or after a zone change
+-- with the map still closed -- there is nothing to match a quest against and every button would
+-- hide itself. The client can build them without the map being shown, and doing so does not disturb
+-- which quest is currently supertracked. Skipped while the map is open so we never fight the player.
+function TrackerUtils:PrimeSuperTrackFrames()
+    if WorldMapFrame and WorldMapFrame:IsShown() then
+        return
+    end
+
+    if WorldMapFrame_UpdateQuests then
+        WorldMapFrame_UpdateQuests()
+    end
+end
+
+---@return table|nil frame, function|nil clickHandler
+local function GetSuperTrackFrame(questId)
+    if (not questId) or questId == 0 then
+        return nil
+    end
+
+    -- Blizzard watch frame POI buttons carry the quest id directly. Questie empties the Blizzard
+    -- watch list (see QuestieTracker:AQW_Insert) so only a handful of quests ever have one. Both
+    -- scans below stop at the first gap: these frames are created in order, so a missing index
+    -- means there are no further ones and this runs once per quest line per redraw.
+    if WatchFrameQuestPOI_OnClick then
+        for i = 1, 30 do
+            local firstInRow = _G["poiWatchFrameLines" .. i .. "_1"]
+            if not firstInRow then
+                break
+            end
+            for j = 1, 5 do
+                local poiButton = (j == 1) and firstInRow or _G["poiWatchFrameLines" .. i .. "_" .. j]
+                if not poiButton then
+                    break
+                end
+                if poiButton.questId == questId then
+                    return poiButton, WatchFrameQuestPOI_OnClick
+                end
+            end
+        end
+    end
+
+    -- World map quest frames cover every quest with a POI on the currently viewed map, which is the
+    -- wider net of the two. Pass the WorldMapQuestFrame itself and never its poiIcon --
+    -- WorldMapFrame_SelectQuestFrame indexes questFrame.poiIcon and errors on the POI frame.
+    if WorldMapFrame_SelectQuestFrame then
+        if not _G["WorldMapQuestFrame1"] then
+            TrackerUtils:PrimeSuperTrackFrames()
+        end
+
+        for i = 1, 25 do
+            local questFrame = _G["WorldMapQuestFrame" .. i]
+            if not questFrame then
+                break
+            end
+            if questFrame.questId == questId then
+                return questFrame, WorldMapFrame_SelectQuestFrame
+            end
+        end
+    end
+
+    return nil
+end
+
+-- A quest can only be supertracked while it has a POI frame, so quests in another zone or without
+-- map coordinates simply have no button.
+function TrackerUtils:CanSuperTrackQuest(questId)
+    return GetSuperTrackFrame(questId) ~= nil
+end
+
+-- The map pin the client draws for this quest. Copying its texture coordinates is what keeps the
+-- tracker button identical to the pin: the number, the "?" shown for completed quests and the
+-- black-on-yellow selected variant all follow along without us mapping atlas cells by hand. The
+-- number is also the pin's position among quests that actually have a POI, which is not the same as
+-- the quest frame index -- another reason to read it from the client instead of deriving it.
+---@return table|nil
+function TrackerUtils:GetSuperTrackPin(questId)
+    if (not questId) or questId == 0 or (not WorldMapFrame_SelectQuestFrame) then
+        return nil
+    end
+
+    if not _G["WorldMapQuestFrame1"] then
+        TrackerUtils:PrimeSuperTrackFrames()
+    end
+
+    for i = 1, 25 do
+        local questFrame = _G["WorldMapQuestFrame" .. i]
+        if not questFrame then
+            break
+        end
+        if questFrame.questId == questId then
+            -- ownPOI is the pin drawn in the map's quest list, poiIcon the one on the map itself.
+            -- The list version is the one we mirror: it keeps the circular background on completed
+            -- quests, where the map version draws a bare "?".
+            return questFrame.ownPOI or questFrame.poiIcon
+        end
+    end
+
+    return nil
+end
+
+function TrackerUtils:SetSuperTrackedQuest(questId)
+    local frame, clickHandler = GetSuperTrackFrame(questId)
+    if not frame then
+        return false
+    end
+
+    clickHandler(frame)
+    return true
+end
+
 function TrackerUtils:IsVoiceOverLoaded()
     -- Require not just that the VoiceOver addons are loaded, but that the runtime
     -- structure we index actually exists. Some VoiceOver builds (e.g. on Elune) expose