feat: 增加NPC范鲸晶

- player场景增加RayCast2D
- 增加npc场景
- 增加NPC对话气泡

scenes/characters/PlayerController.gd

@@ -9,6 +9,7 @@ const MOVE_SPEED = 200.0
 # 节点引用
 @onready var animation_player: AnimationPlayer = $AnimationPlayer
 @onready var sprite: Sprite2D = $Sprite2D
+@onready var ray_cast: RayCast2D = $RayCast2D
 
 var last_direction := "down"
 
@@ -19,6 +20,11 @@ func _ready() -> void:
 	# 播放初始动画
 	if animation_player.has_animation("idle"):
 		animation_player.play("idle")
+		
+	# Initialize RayCast
+	ray_cast.add_exception(self) # Ignore local player
+	ray_cast.enabled = true
+	ray_cast.target_position = Vector2(0, 60)
 	
 func _check_spawn_position() -> void:
 	var spawn_pos = SceneManager.get_next_scene_position()
@@ -27,6 +33,14 @@ func _check_spawn_position() -> void:
 
 func _physics_process(delta: float) -> void:
 	_handle_movement(delta)
+	_handle_interaction()
+
+func _handle_interaction() -> void:
+	if Input.is_action_just_pressed("interact"):
+		if ray_cast.is_colliding():
+			var collider = ray_cast.get_collider()
+			if collider and collider.has_method("interact"):
+				collider.interact()
 
 func _handle_movement(_delta: float) -> void:
 	# 获取移动向量 (参考 docs/02-开发规范/输入映射配置.md)
@@ -59,13 +73,17 @@ func _update_animation_state(direction: Vector2) -> void:
 	if abs(direction.x) > abs(direction.y):
 		if direction.x > 0:
 			last_direction = "right"
+			ray_cast.target_position = Vector2(60, 0)
 		else:
 			last_direction = "left"
+			ray_cast.target_position = Vector2(-60, 0)
 	else:
 		if direction.y > 0:
 			last_direction = "down"
+			ray_cast.target_position = Vector2(0, 60)
 		else:
 			last_direction = "up"
+			ray_cast.target_position = Vector2(0, -60)
 	
 	animation_player.play("walk_" + last_direction)