Add Comprehensive Dungeon Editor Design Plan

- Introduced a detailed design plan document for the Yaze Dungeon Editor, outlining the current architecture, main components, and core systems.
- Documented identified issues and applied fixes, including crash prevention and UI simplification, along with a roadmap for future development phases.
- Enhanced clarity on the implementation guidelines, testing strategies, and performance considerations to support ongoing development efforts.
- Established a structured approach for new developers to understand the codebase and contribute effectively to the project.

src/app/editor/dungeon/dungeon_room_selector.cc

@@ -10,9 +10,28 @@
 namespace yaze::editor {
 
 using ImGui::BeginChild;
+using ImGui::BeginTabBar;
+using ImGui::BeginTabItem;
 using ImGui::EndChild;
+using ImGui::EndTabBar;
+using ImGui::EndTabItem;
 using ImGui::Separator;
 using ImGui::SameLine;
+using ImGui::Text;
+
+void DungeonRoomSelector::Draw() {
+  if (ImGui::BeginTabBar("##DungeonRoomTabBar")) {
+    if (ImGui::BeginTabItem("Rooms")) {
+      DrawRoomSelector();
+      ImGui::EndTabItem();
+    }
+    if (ImGui::BeginTabItem("Entrances")) {
+      DrawEntranceSelector();
+      ImGui::EndTabItem();
+    }
+    ImGui::EndTabBar();
+  }
+}
 
 void DungeonRoomSelector::DrawRoomSelector() {
   if (!rom_ || !rom_->is_loaded()) {