feat(poc): implement Sprint 1 proof of concept

- project.godot with autoload configuration
- Reception room with placeholder visuals
- Draggable Character with DragDropComponent
- Interactive flower object with bounce animation
- GameState, SaveManager, AudioManager, InputManager autoloads
- HUD with back button and music toggle

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/objects/interactive_object.gd

@@ -0,0 +1,57 @@
+## InteractiveObject — base class for all interactive room objects (flowers, equipment, etc.).
+class_name InteractiveObject extends Node2D
+
+signal object_interacted(object: InteractiveObject)
+
+enum State { IDLE, ACTIVE, RETURNING }
+
+@export var object_id: String = ""
+
+var _current_state: State = State.IDLE
+
+
+func _ready() -> void:
+	var drag: DragDropComponent = get_node_or_null("DragDropComponent") as DragDropComponent
+	if drag != null:
+		drag.drag_picked_up.connect(_on_drag_picked_up)
+		drag.drag_released.connect(_on_drag_released)
+	var area: Area2D = get_node_or_null("CollisionArea") as Area2D
+	if area != null:
+		area.input_event.connect(_on_area_input_event)
+
+
+func _on_drag_picked_up(_pos: Vector2) -> void:
+	_set_state(State.ACTIVE)
+	object_interacted.emit(self)
+
+
+func _on_drag_released(_pos: Vector2) -> void:
+	_set_state(State.RETURNING)
+	GameState.set_object_state(object_id, "idle")
+	_play_bounce_animation()
+
+
+func _on_area_input_event(_viewport: Node, event: InputEvent, _shape_idx: int) -> void:
+	if event is InputEventMouseButton and event.pressed and event.button_index == MOUSE_BUTTON_LEFT:
+		_trigger_interaction()
+	elif event is InputEventScreenTouch and event.pressed:
+		_trigger_interaction()
+
+
+func _trigger_interaction() -> void:
+	_set_state(State.ACTIVE)
+	object_interacted.emit(self)
+	GameState.set_object_state(object_id, "active")
+	_play_bounce_animation()
+
+
+func _set_state(new_state: State) -> void:
+	_current_state = new_state
+
+
+func _play_bounce_animation() -> void:
+	var tween: Tween = create_tween()
+	tween.tween_property(self, "scale", Vector2(1.2, 1.2), 0.1)
+	tween.tween_property(self, "scale", Vector2(0.9, 0.9), 0.1)
+	tween.tween_property(self, "scale", Vector2(1.0, 1.0), 0.1)
+	tween.tween_callback(func() -> void: _set_state(State.IDLE))