game: add levelups

scenes/managers/ui/level_up_ui.gd

@@ -0,0 +1,15 @@
+class_name LevelUpUI
+extends Control
+
+@onready var choice_container: HBoxContainer = $VBoxContainer/PanelContainer/CenterContainer/ChoiceContainer
+
+func clear():
+	for child in choice_container.get_children():
+		child.queue_free()
+
+func add_choice(choice: LevelUpChoice) -> void:
+	choice.lvlup_picked.connect(_on_levelup_picked)
+	choice_container.add_child(choice)
+
+func _on_levelup_picked(mod: PlayerStatsModifier) -> void:
+	visible = false