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.

DataStore_Quests/DataStore_Quests.lua

@@ -274,8 +274,10 @@ local function _GetQuestLogRewardInfo(character, index, rewardIndex)
 end
 	
 local function _GetQuestInfo(link)
-	assert(type(link) == "string")
-	
+	-- CoA: GetQuestLogInfo can hand back a nil link for a partial-data alt; degrade to nil
+	-- returns instead of asserting (callers already nil-check the returned name/level).
+	if type(link) ~= "string" then return end
+
 	local questID, questLevel = link:match("quest:(%d+):(-?%d+)")
 	local questName = link:match("%[(.+)%]")