docs: store checked zero-context UI entry proposal

docs/plans/original-completion-2026-10-02/execution/p24-02/native-os-input-r01/proposed-normal-save-entry.patch

@@ -1,24 +1,11 @@
 --- a/scenes/main/main.gd
 +++ b/scenes/main/main.gd
-@@ -790,17 +790,19 @@
- 	row.add_child(audio_button)
- 	var load_menu := MenuButton.new()
- 	load_menu.name = "SaveLoadMenu"
+@@ -793 +793 @@
 -	load_menu.text = "読込 ▾"
 +	load_menu.text = "保存・読込 ▾"
- 	load_menu.custom_minimum_size = Vector2(64,28)
- 	load_menu.add_theme_font_size_override("font_size",12)
- 	_apply_button_style(load_menu)
- 	load_menu.get_popup().add_item("手動セーブを読み込む",0)
- 	load_menu.get_popup().add_item("旧寸法を修正して読み込む",1)
- 	load_menu.get_popup().add_item("保存スロットを選んで読込",2)
+@@ -799,0 +800 @@
 +	load_menu.get_popup().add_item("新しい名前で別スロット保存",3)
- 	load_menu.get_popup().id_pressed.connect(func(id: int):
- 		if id == 0: _load_manual()
- 		elif id == 1: _preview_dimension_migration()
+@@ -803 +804,2 @@
 -		elif id == 2: _show_manual_load_slots())
 +		elif id == 2: _show_manual_load_slots()
 +		elif id == 3: _ensure_manual_save_slots().show_new_save(manual_save_path))
- 	row.add_child(load_menu)
- 
- 	palette_scroll = ScrollContainer.new()