coa.17: comprehensive partial-data hardening + DataStore_Characters login scan + Skills strip cap

- Hardening sweep across DataStore_* (softened crash-asserts in Talents/Containers/Quests
  to graceful nil) + Altoholic frames (guarded remaining getter results).
- DataStore_Characters: scan on login (was ghost-gated -> name/level/class never populated;
  the core 'no character data' cause).
- Skills tab: cap inline professions at 6 (+N) so the strip stops overflowing into Cooking.

Altoholic/Frames/Containers.lua

@@ -177,8 +177,8 @@ local function UpdateSpread()
 				
 				local slotID = bagIndices[line].from - 3 + j
 				local itemID, itemLink, itemCount = DS:GetSlotInfo(container, slotID)
-				
-				if (slotID <= containerSize) then 
+
+				if (slotID <= (containerSize or 0)) then 		-- CoA: containerSize nil for unscanned bag on partial-data alt
 					if itemID then
 						Altoholic:SetItemButtonTexture(itemName, GetItemIcon(itemID));
 						
@@ -278,7 +278,7 @@ local function UpdateAllInOne()
 		local container = DS:GetContainer(character, containerID)
 		local _, _, containerSize = DS:GetContainerInfo(character, containerID)
 
-		for slotID = 1, containerSize do
+		for slotID = 1, (containerSize or 0) do		-- CoA: containerSize nil for unscanned bag on partial-data alt
 			local itemID, itemLink, itemCount = DS:GetSlotInfo(container, slotID)
 			if itemID then
 				currentSlotIndex = currentSlotIndex + 1