coa.5: refactor char display into guarded helpers; fix missed sites; restore login scan

- Extract AddCharacterTooltipHeader() + SetCharacterRowNameLevel() (Altoholic.lua);
  nil-guards centralized, callers in AccountSummary/Activity/BagUsage/Skills/tooltip.
- Fix sites the manual sweep missed: Skills.lua (row + skill ranks), Keys.lua x3,
  ShowClassIcons sort (Altoholic.lua:705, getters bypass their own or-0 via the wrapper).
- Restore login scan: OnPlayerAlive was ghost-only (fdcb25a) so iLvl never populated;
  now scans once per session. Removed dated DEBUG leftovers.

Altoholic/Frames/Keys.lua

@@ -789,7 +789,7 @@ function ns:Item_OnEnter(frame)
 		
 		AltoTooltip:SetOwner(frame, "ANCHOR_LEFT")
 		AltoTooltip:ClearLines()
-		AltoTooltip:AddLine( format("%s|r: %s", DS:GetColoredCharacterName(character), nameKey) )
+		AltoTooltip:AddLine( format("%s|r: %s", DS:GetColoredCharacterName(character) or "?", nameKey) )
 		AltoTooltip:AddLine(" ")
 		
 		local questDone, cr,cg,cb
@@ -848,7 +848,7 @@ function ns:Item_OnEnter(frame)
 		else
 			AltoTooltip:SetOwner(frame, "ANCHOR_LEFT")
 			AltoTooltip:ClearLines()
-			AltoTooltip:AddLine( format("%s|r: %s", DS:GetColoredCharacterName(character), nameKey) )
+			AltoTooltip:AddLine( format("%s|r: %s", DS:GetColoredCharacterName(character) or "?", nameKey) )
 			AltoTooltip:AddLine(" ")
 			
 			local questDone, cr,cg,cb
@@ -912,7 +912,7 @@ function ns:Item_OnEnter(frame)
 		else
 			AltoTooltip:SetOwner(frame, "ANCHOR_LEFT")
 			AltoTooltip:ClearLines()
-			AltoTooltip:AddLine( format("%s|r: %s", DS:GetColoredCharacterName(character), nameKey) )
+			AltoTooltip:AddLine( format("%s|r: %s", DS:GetColoredCharacterName(character) or "?", nameKey) )
 			AltoTooltip:AddLine(" ")
 			AltoTooltip:AddLine(L["Required reputation"] .. ":",1,1,1)