Main: Overview UI wiring for the new escape menu

- Overview UI canvas active, OverviewMenu component wired to panel,
  browser reference and mode buttons; includes YAML reshuffle from the
  scene re-save (content verified unchanged).
- EditorSettings: known 1-line churn.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

ProjectSettings/EditorSettings.asset

@@ -25,7 +25,7 @@ EditorSettings:
   m_AsyncShaderCompilation: 1
   m_PrefabModeAllowAutoSave: 1
   m_EnterPlayModeOptionsEnabled: 1
-  m_EnterPlayModeOptions: 0
+  m_EnterPlayModeOptions: 3
   m_GameObjectNamingDigits: 1
   m_GameObjectNamingScheme: 0
   m_AssetNamingUsesSpace: 1