fix: guard item name lookup against invalid ids

Database/QuestieDB.lua

@@ -321,6 +321,19 @@ if not Item then
 end
 
 if not Item.CreateFromItemID then
+    local function SafeGetItemName(itemID)
+        local numericItemID = tonumber(itemID)
+        if not numericItemID or numericItemID == 0 then
+            return "item:" .. tostring(itemID)
+        end
+
+        local ok, name = pcall(GetItemInfo, numericItemID)
+        if not ok then
+            return "item:" .. tostring(numericItemID)
+        end
+        return name or ("item:" .. tostring(numericItemID))
+    end
+
     function Item:CreateFromItemID(itemID)
         local obj = {}
 
@@ -332,8 +345,7 @@ if not Item.CreateFromItemID then
         end
 
         function obj:GetItemName()
-            local name = GetItemInfo(itemID)
-            return name or ("item:" .. tostring(itemID))
+            return SafeGetItemName(itemID)
         end
 
         return obj

Tests/QuestieItemNameSafety_spec.lua

@@ -0,0 +1,19 @@
+describe("Questie item name safety", function()
+    before_each(function()
+        dofile("Tests/wow_api_mock.lua")
+        GetItemInfo = function()
+            error("GetItemInfo should not be called for invalid item ids")
+        end
+        dofile("Database/QuestieDB.lua")
+    end)
+
+    it("returns a placeholder instead of calling GetItemInfo for invalid item ids", function()
+        local item = Item:CreateFromItemID(nil)
+        assert.equals("item:nil", item:GetItemName())
+    end)
+
+    it("also handles non-numeric item ids safely", function()
+        local item = Item:CreateFromItemID("bad-id")
+        assert.equals("item:bad-id", item:GetItemName())
+    end)
+end)