Resolved first comments and made StageDrawings explicit classes that now also follow lane identifiers

src/classes/persistence/Persistence.lua

@@ -33,6 +33,7 @@ do
         unitsStates = {},
         random_missions = {},
         deliveredKilos = {},
+        activeStage = nil, -- Backwards compatibility for previous version without lanes
         activeStageInStageLane = {}
     }
 
@@ -238,6 +239,21 @@ do
         Persistence._updateRequired = true
     end
 
+    ---Get the active stage as in the persistance file
+    ---@param stageLane string?
+    ---@return integer|nil
+    Persistence.GetActiveStage = function(stageLane)
+        stageLane = stageLane or "nil"
+
+        -- backwards compatibility for previous versions without stage lanes
+        if stageLane == "nil" and tables.activeStageInStageLane[stageLane] == nil then
+            tables.activeStageInStageLane[stageLane] = tables.activeStage
+            tables.activeStage = nil -- Clear the old activeStage so it's not used or confused later
+        end
+
+        return tables.activeStageInStageLane[stageLane]
+    end
+
     ---comment
     ---@param missionName string
     ---@param pickedZone string
@@ -257,13 +273,6 @@ do
         return tables.random_missions[string.lower(missionName)]
     end
 
-    ---Get the active stage as in the persistance file
-    ---@param stageLane string?
-    ---@return integer|nil
-    Persistence.GetActiveStage = function(stageLane)
-        stageLane = stageLane or "nil"
-        return tables.activeStageInStageLane[stageLane]
-    end
 
     ---comment
     ---@param zoneName string