feat: Refactor editor structure and enhance multi-session support

- Moved `menu_builder.cc` to a new `ui` directory for better organization.
- Updated `EditorManager` to generate unique ImGui IDs for multi-session support, ensuring separate window handling.
- Added session ID management in `EditorContext` for improved child panel identification.
- Introduced a new `MenuBuilder` class for streamlined ImGui menu creation, enhancing UI maintainability.

src/app/editor/editor.h

@@ -28,6 +28,11 @@ struct EditorContext {
   HistoryManager history_manager;
   PopupManager* popup_manager = nullptr;
   ShortcutManager shortcut_manager;
+  
+  // Session identification for multi-session support
+  // Used by child panels to create unique ImGui IDs
+  size_t session_id = 0;
+  
   // Cross-session shared clipboard for editor data transfers
   struct SharedClipboard {
     // Overworld tile16 selection payload

src/app/editor/editor_library.cmake

@@ -1,7 +1,7 @@
 set(
   YAZE_APP_EDITOR_SRC
   app/editor/editor_manager.cc
-  app/editor/menu_builder.cc
+  app/editor/ui/menu_builder.cc
   app/editor/ui/editor_selection_dialog.cc
   app/editor/ui/welcome_screen.cc
   app/editor/ui/background_renderer.cc

src/app/editor/editor_manager.cc

@@ -992,18 +992,31 @@ absl::Status EditorManager::Update() {
           }
         }
 
-        // Generate unique window titles for multi-session support
+        // Generate unique window titles and IDs for multi-session support
         std::string window_title =
             GenerateUniqueEditorTitle(editor->type(), session_idx);
         
-        if (ImGui::Begin(window_title.c_str(), editor->active())) {
+        // Create truly unique ImGui ID combining session index and editor type
+        // This ensures ImGui treats them as completely separate windows
+        ImGui::PushID(static_cast<int>(session_idx * 100 + static_cast<int>(editor->type())));
+
+        // Set window to maximize on first open
+        if (ImGui::IsWindowAppearing()) {
+          ImGui::SetNextWindowSize(ImGui::GetMainViewport()->WorkSize, ImGuiCond_Appearing);
+          ImGui::SetNextWindowPos(ImGui::GetMainViewport()->WorkPos, ImGuiCond_Appearing);
+        }
+        
+        if (ImGui::Begin(window_title.c_str(), editor->active(), 
+                        ImGuiWindowFlags_None)) {  // Allow full docking
           // Temporarily switch context for this editor's update
           Rom* prev_rom = current_rom_;
           EditorSet* prev_editor_set = current_editor_set_;
+          size_t prev_session_id = context_.session_id;
 
           current_rom_ = &session.rom;
           current_editor_set_ = &session.editors;
           current_editor_ = editor;
+          context_.session_id = session_idx;  // Set session ID for child panels
 
           status_ = editor->Update();
 
@@ -1034,8 +1047,10 @@ absl::Status EditorManager::Update() {
           // Restore context
           current_rom_ = prev_rom;
           current_editor_set_ = prev_editor_set;
+          context_.session_id = prev_session_id;  // Restore previous session ID
         }
         ImGui::End();
+        ImGui::PopID();  // Pop the unique ID for this session+editor combination
       }
     }
   }

src/app/editor/editor_manager.h

@@ -13,6 +13,7 @@
 #include "app/core/project.h"
 #include "app/editor/code/assembly_editor.h"
 #include "app/editor/code/memory_editor.h"
+#include "app/editor/code/memory_editor_enhanced.h"
 #include "app/editor/code/project_file_editor.h"
 #include "app/editor/dungeon/dungeon_editor_v2.h"
 #include "app/editor/graphics/graphics_editor.h"

src/app/editor/ui/menu_builder.cc

@@ -1,4 +1,4 @@
-#include "app/editor/menu_builder.h"
+#include "app/editor/ui/menu_builder.h"
 
 #include "absl/strings/str_cat.h"
 

src/app/editor/ui/menu_builder.h

@@ -1,5 +1,5 @@
-#ifndef YAZE_APP_EDITOR_MENU_BUILDER_H_
+#ifndef YAZE_APP_EDITOR_UI_MENU_BUILDER_H_
-#define YAZE_APP_EDITOR_MENU_BUILDER_H_
+#define YAZE_APP_EDITOR_UI_MENU_BUILDER_H_
 
 #include <functional>
 #include <string>
@@ -116,4 +116,4 @@ class MenuBuilder {
 }  // namespace editor
 }  // namespace yaze
 
-#endif  // YAZE_APP_EDITOR_MENU_BUILDER_H_
+#endif  // YAZE_APP_EDITOR_UI_MENU_BUILDER_H_