Convert remaining editors to use ActionButton

- object_defs_view.lua: 2 buttons (Brush, Add)
- areas_window.lua: 1 button (Add area)
- triggers_window.lua: 1 button (Add trigger)
- variables_window.lua: 1 button (Add variable)
- array_field.lua: 1 button (Add item)
- dnts_editor.lua: 1 button (DNTS)

Fixes crashes when these editors initialize in RmlUi mode.
All editors now use ActionButton wrapper instead of direct
TabbedPanelButton, enabling proper icon display in both modes.

Author: claude

scen_edit/view/fields/array_field.lua

@@ -131,7 +131,7 @@ function ArrayFieldWindow:init(opts)
     self.OnUpdateItem = opts.OnUpdateItem
 
     if self.field.canAdd then
-        self.btnAddItem = TabbedPanelButton({
+        self.btnAddItem = ActionButton({
             x = 0,
             y = 0,
             tooltip = "Add",

scen_edit/view/map/dnts_editor.lua

@@ -75,7 +75,7 @@ function DNTSEditor:init()
         },
     })
 
-    self.btnDNTS = TabbedPanelButton({
+    self.btnDNTS = ActionButton({
         x = 140,
         y = 0,
         tooltip = "DNTS textures",

scen_edit/view/object/object_defs_view.lua

@@ -5,7 +5,7 @@ ObjectDefsView = Editor:extends{}
 function ObjectDefsView:init()
     self:super("init")
 
-    self.btnBrush = TabbedPanelButton({
+    self.btnBrush = ActionButton({
         x = 0,
         y = 0,
         tooltip = "Add or remove objects by painting the map",
@@ -20,7 +20,7 @@ function ObjectDefsView:init()
             end
         },
     })
-    self.btnSet = TabbedPanelButton({
+    self.btnSet = ActionButton({
         x = 70,
         y = 0,
         tooltip = "Add objects by clicking on the map",

scen_edit/view/trigger/areas_window.lua

@@ -14,7 +14,7 @@ AreasWindow:Register({
 function AreasWindow:init()
     self:super("init")
 
-    self.btnAddArea = TabbedPanelButton({
+    self.btnAddArea = ActionButton({
         x = 0,
         y = 0,
         tooltip = "Add area",

scen_edit/view/trigger/triggers_window.lua

@@ -13,7 +13,7 @@ TriggersWindow:Register({
 function TriggersWindow:init()
     self:super("init")
 
-    self.btnAddTrigger = TabbedPanelButton({
+    self.btnAddTrigger = ActionButton({
         x = 0,
         y = 0,
         tooltip = "Add trigger",

scen_edit/view/trigger/variables_window.lua

@@ -13,7 +13,7 @@ VariablesWindow:Register({
 function VariablesWindow:init()
     self:super("init")
 
-    self.btnAddVariable = TabbedPanelButton({
+    self.btnAddVariable = ActionButton({
         x = 0,
         y = 0,
         tooltip = "Add variable",