refactor(docs): update editor status and welcome screen logic in documentation

- Revised the editor status section to reflect the current state of various editors, including stability notes and testing requirements.
- Clarified the welcome screen visibility logic in the documentation, emphasizing its behavior when no ROM is loaded and the conditions for manual control.
- Enhanced the overall structure and clarity of the development guide to better inform contributors about the project's status and UI management practices.

Benefits:
- Provides a clearer understanding of the current capabilities and testing needs of the editors.
- Improves documentation accuracy regarding UI behavior, aiding developers in troubleshooting and feature implementation.

src/app/editor/editor_manager.cc

@@ -712,6 +712,12 @@ absl::Status EditorManager::Update() {
     last_test_rom = current_rom_;
   }
 
+  // CRITICAL: Draw UICoordinator UI components FIRST (before ROM checks)
+  // This ensures Welcome Screen, Command Palette, etc. work even without ROM loaded
+  if (ui_coordinator_) {
+    ui_coordinator_->DrawAllUI();
+  }
+
   // Autosave timer
   if (user_settings_.prefs().autosave_enabled && current_rom_ &&
       current_rom_->dirty()) {
@@ -735,13 +741,13 @@ absl::Status EditorManager::Update() {
 
   // Check if ROM is loaded before allowing editor updates
   if (!current_editor_set_) {
-    // Note: Welcome screen auto-show is now handled by UICoordinator
+    // No ROM loaded - welcome screen shown by UICoordinator above
     return absl::OkStatus();
   }
 
   // Check if current ROM is valid
   if (!current_rom_) {
-    // Note: Welcome screen auto-show is now handled by UICoordinator
+    // No ROM loaded - welcome screen shown by UICoordinator above
     return absl::OkStatus();
   }
 
@@ -911,19 +917,9 @@ absl::Status EditorManager::Update() {
   if (session_coordinator_) {
     session_coordinator_->DrawSessionSwitcher();
     session_coordinator_->DrawSessionManager();
-    // TODO: Decide which is actually used.
-    // if (ui_coordinator_) {
-    //   ui_coordinator_->DrawSessionManager();
-    // }
     session_coordinator_->DrawSessionRenameDialog();
   }
 
-  // Draw UICoordinator UI components (Command Palette, Global Search, etc.)
-  // CRITICAL: This must be called for Command Palette and other UI windows to appear
-  if (ui_coordinator_) {
-    ui_coordinator_->DrawAllUI();
-  }
-
   return absl::OkStatus();
 }