feat(navigation): add NavigationArrow component for within-floor room navigation

scripts/objects/navigation_arrow.gd

@@ -0,0 +1,40 @@
+## NavigationArrow — tappable button that navigates camera to a specific floor and room.
+class_name NavigationArrow extends Node2D
+
+const BUTTON_HALF_SIZE: float = 48.0
+
+@export var target_floor: int = 0
+@export var target_room: int = 0
+@export var label_text: String = "→"
+
+
+func _ready() -> void:
+	var label: Label = get_node_or_null("Label") as Label
+	if label != null:
+		label.text = label_text
+
+
+func _input(event: InputEvent) -> void:
+	var screen_pos: Vector2
+	if event is InputEventScreenTouch and event.pressed:
+		screen_pos = event.position
+	elif event is InputEventMouseButton and event.pressed and event.button_index == MOUSE_BUTTON_LEFT:
+		screen_pos = event.position
+	else:
+		return
+	var canvas_transform: Transform2D = get_viewport().get_canvas_transform()
+	var world_pos: Vector2 = canvas_transform.affine_inverse() * screen_pos
+	var local_pos: Vector2 = to_local(world_pos)
+	if abs(local_pos.x) <= BUTTON_HALF_SIZE and abs(local_pos.y) <= BUTTON_HALF_SIZE:
+		_on_pressed()
+
+
+func _on_pressed() -> void:
+	RoomNavigator.go_to_room(target_floor, target_room)
+	_play_bounce()
+
+
+func _play_bounce() -> void:
+	var tween: Tween = create_tween()
+	tween.tween_property(self, "scale", Vector2(1.15, 1.15), 0.08)
+	tween.tween_property(self, "scale", Vector2(1.0, 1.0), 0.08)