Use existing MainWindowPanel for both Chili and RmlUi modes

Instead of creating parallel initialization systems, reuse what exists.

Changes:
1. MainWindowPanel:AddElement() now detects RmlUi mode
   - In RmlUi: skips Chili button creation, uses SB.delay for editors
   - In Chili: creates buttons and editors as before

2. View:InitializeRmlUi() now creates TabbedWindow (like Chili does)
   - TabbedWindow creates MainWindowPanels
   - MainWindowPanel:AddElements() populates from editorRegistry
   - Editor creation happens via existing SB.delay mechanism

3. Removed custom PreCreateAllEditors() - not needed

This unifies the editor initialization path for both UI systems.
Both modes now use the same TabbedWindow/MainWindowPanel infrastructure,
with MainWindowPanel detecting the mode and adapting behavior.

Author: claude

scen_edit/view/main_window/main_window_panel.lua

@@ -94,6 +94,18 @@ function MainWindowPanel:AddElement(tbl)
     local name = tbl.name
     local editor = tbl.editor
 
+    -- In RmlUi mode, skip Chili button creation but still create editors
+    if SB.view and SB.view.useRmlUi then
+        SB.delay(function()
+            if not SB.editors[name] then
+                SB.editors[name] = editor()
+            end
+        end)
+        self._totalEditors = self._totalEditors + 1
+        return
+    end
+
+    -- Chili mode: create button and editor
     local btn = TabbedPanelButton({
         tooltip = tooltip,
         children = {

scen_edit/view/view.lua

@@ -68,35 +68,21 @@ function View:InitializeRmlUi()
         SB.editors = {}
     end
 
+    -- Use existing TabbedWindow/MainWindowPanel infrastructure (works in both modes)
+    -- This handles editor creation via SB.delay automatically
+    self.tabbedWindow = TabbedWindow()
+
     -- Initialize tab system
     self.currentTab = "Objects"
     self:BindTabEvents()
     self:PopulateEditorButtons(self.currentTab)
 
-    -- Pre-create ALL editors using SB.delay (matching Chili's approach)
-    -- This catches errors early while avoiding SB.view nil issues
-    self:PreCreateAllEditors()
-
     -- Setup event handlers
     self:SetupRmlUiEvents()
 
     Log.Notice("RmlUi UI initialized successfully - editors use field compatibility layer")
 end
 
-function View:PreCreateAllEditors()
-    -- Pre-create all registered editors using SB.delay
-    -- This matches the original Chili approach in main_window_panel.lua
-    -- Defers creation until after SB.view is assigned
-    for name, editorCfg in pairs(SB.editorRegistry) do
-        SB.delay(function()
-            if not SB.editors[name] and editorCfg.editor then
-                Log.Notice("Pre-creating editor: " .. name)
-                SB.editors[name] = editorCfg.editor()
-            end
-        end)
-    end
-end
-
 function View:SetupRmlUiEvents()
     if not self.mainDocument then
         return
@@ -360,7 +346,7 @@ end
 function View:OpenEditor(editorName)
     Log.Notice("Opening editor: " .. editorName)
 
-    -- Editor should be pre-created by PreCreateAllEditors()
+    -- Editor should be pre-created by TabbedWindow/MainWindowPanel
     local editor = SB.editors[editorName]
     if not editor then
         Log.Error("Editor not yet created: " .. editorName .. " (still initializing?)")