Add wrapping keyboard and gamepad focus rings

- Link every modal's enabled controls into a wrapping UiFocus ring and give each screen a default focus target.
- Add gamepad A/B bindings for ui_accept/ui_cancel; include Start menu footer actions and Continue in its focus ring.
- Skip hidden/disabled controls, close focus traps via per-modal cancel behavior, and return review to the menu on cancel.
- Record the focus audit and add regression coverage.

src/game/ui/pause_overlay.gd

@@ -11,10 +11,12 @@ signal quit_to_menu_requested()
 
 const UiArt := preload("res://src/game/ui/art.gd")
 const UiStyles := preload("res://src/game/ui/ui_styles.gd")
+const UiFocus := preload("res://src/game/ui/ui_focus.gd")
 const Strings := preload("res://src/core/strings.gd")
 
 var _root: Control = null
 var _resume_button: Button = null
+var _buttons: Array[Button] = []
 
 func _ready() -> void:
 	layer = 18
@@ -53,9 +55,11 @@ func _build() -> void:
 	column.add_child(title)
 
 	_resume_button = _add_button(column, Strings.lookup("ui.pause_resume"), "ResumeButton", func(): resume_requested.emit())
-	_add_button(column, Strings.lookup("ui.pause_restart"), "RestartButton", func(): restart_requested.emit())
-	_add_button(column, Strings.lookup("ui.pause_settings"), "SettingsButton", func(): settings_requested.emit())
-	_add_button(column, Strings.lookup("ui.pause_menu"), "MenuButton", func(): quit_to_menu_requested.emit())
+	_buttons.append(_add_button(column, Strings.lookup("ui.pause_restart"), "RestartButton", func(): restart_requested.emit()))
+	_buttons.append(_add_button(column, Strings.lookup("ui.pause_settings"), "SettingsButton", func(): settings_requested.emit()))
+	_buttons.append(_add_button(column, Strings.lookup("ui.pause_menu"), "MenuButton", func(): quit_to_menu_requested.emit()))
+	_buttons.push_front(_resume_button)
+	UiFocus.link(_buttons)
 
 	var hint := Label.new()
 	hint.text = Strings.lookup("ui.pause_hint")
@@ -77,6 +81,7 @@ func open() -> void:
 	visible = true
 	_root.visible = true
 	Input.set_mouse_mode(Input.MOUSE_MODE_VISIBLE)
+	UiFocus.link(_buttons)
 	if _resume_button:
 		_resume_button.grab_focus()
 
@@ -87,6 +92,6 @@ func close() -> void:
 func _unhandled_input(event: InputEvent) -> void:
 	if not visible:
 		return
-	if event is InputEventKey and event.pressed and not event.echo and event.keycode == KEY_ESCAPE:
+	if event.is_action_pressed("ui_cancel"):
 		resume_requested.emit()
 		get_viewport().set_input_as_handled()