Update notes and fix scene lifestyle issues

NOTES.md

@@ -16,9 +16,10 @@ A selected object is not just a rectangle. It may be authored, runtime-created,
 
 ## Must do first
 
-- Keep player/controller ownership scene-specific unless a genuinely shared abstraction appears.
-- Introduce an editor command/change model before implementing undo/redo.
-- Keep undo/redo editor-only at first.
+- [x] Keep player/controller ownership scene-specific unless a genuinely shared abstraction appears.
+- [x] Introduce an editor command/change model before implementing undo/redo.
+- [x] Keep undo/redo editor-only at first.
+- [x] Keep scene activation separate from default scene creation so loading cannot be overwritten by `on_enter()`.
 
 ## Phase targets
 

README.md

@@ -192,7 +192,8 @@ Current priorities:
 - [x] Command model for editor changes
 - [x] Undo/Redo on top of the command model
 - [x] Command history panel
-- [ ] Multi-select
+- [x] Multi-select
+- [x] Multi-select move/delete
 - [ ] Tool mode state
 - [ ] Scale tool
 - [ ] Basic audio hooks

src/prune/app/app.cpp

@@ -28,6 +28,7 @@ namespace prune {
         m_input = std::make_unique<Input>();
         m_time = std::make_unique<Time>();
         m_scene = SceneFactory::create(SceneType::Platformer, m_window->width(), m_window->height());
+        m_scene->new_scene();
         m_scene->on_enter();
         m_ui = std::make_unique<Ui>();
 
@@ -99,7 +100,7 @@ namespace prune {
                         m_window->height()
                     );
 
-					m_scene->new_scene();
+                    m_scene->new_scene();
                     m_scene->on_enter();
                     m_ui->set_file_status("Created new scene", false);
                 }

src/prune/scene/artillery/artillery_scene.cpp

@@ -82,7 +82,7 @@ namespace prune {
 
     void ArtilleryScene::on_enter()
     {
-        new_scene();
+        // Scene activation hook only. Default content is created explicitly via new_scene().
     }
 
     void ArtilleryScene::on_exit()

src/prune/scene/platformer/platformer_scene.cpp

@@ -72,7 +72,7 @@ namespace prune {
 
     void PlatformerScene::on_enter()
     {
-        new_scene();
+        // Scene activation hook only. Default content is created explicitly via new_scene().
     }
 
     void PlatformerScene::on_exit()

src/prune/scene/scene.hpp

@@ -45,8 +45,12 @@ namespace prune {
         Scene(const Scene&) = delete;
         Scene& operator=(const Scene&) = delete;
 
+        // Called when an already-created scene becomes active. Must not create or restore default content.
         virtual void on_enter() = 0;
+
+        // Creates the default authored content for a new scene. Must not be called after loading a scene from disk.
         virtual void new_scene() = 0;
+
         virtual void on_exit() = 0;
         virtual void update(float dt, const Input& input) = 0;
         virtual void update_editor(float, const Input&) {}

src/prune/scene/simple_shooter/simple_shooter_scene.cpp

@@ -123,7 +123,7 @@ namespace prune {
 
     void SimpleShooterScene::on_enter()
     {
-        new_scene();
+        // Scene activation hook only. Default content is created explicitly via new_scene().
     }
 
     void SimpleShooterScene::on_exit()