fixed a local, made code even smaller

src/core/GameKeyHandler.ttslua

@@ -38,13 +38,9 @@ function triggerUpkeep(playerColor)
     sentMessage = true
   end
   if #Player.getPlayers() == 1 then
-    local colors = Player.getAvailableColors()
-    for _, handColor in ipairs(colors) do
-      local matColor = playermatApi.getMatColor(handColor)
-      local data = playermatApi.getActiveInvestigatorData(matColor)
-      if data.id ~= "00000" then
-        playermatApi.doUpkeepFromHotkey(matColor, playerColor)
-      end
+    local usedMats = playermatApi.getUsedMatColors()
+    for _, matColor in ipairs(usedMats) do
+      playermatApi.doUpkeepFromHotkey(matColor, playerColor)
     end
     playAreaApi.readyCards()
     return

src/core/PlayArea.ttslua

@@ -514,8 +514,9 @@ end
 
 -- Readies all cards in the main playarea (both player cards, treacheries and enemies)
 function readyCards(player, clickType)
+  local playerColor
   if player ~= nil then
-    local playerColor = player.color
+    playerColor = player.color
   else
     local existingPlayer = Player.getPlayers()[1]
     playerColor = existingPlayer.color