feat：增加多角色在线功能

- 增加远程登录角色精灵
- 基于后端接口完成位置同步
- 实现多人在线以及跳转
- 增加个人房间功能

scenes/characters/PlayerController.gd

@@ -0,0 +1,74 @@
+extends CharacterBody2D
+
+# 信号定义
+signal player_moved(position: Vector2)
+
+# 常量定义
+const MOVE_SPEED = 200.0
+
+# 节点引用
+@onready var animation_player: AnimationPlayer = $AnimationPlayer
+@onready var sprite: Sprite2D = $Sprite2D
+
+var last_direction := "down"
+
+func _ready() -> void:
+	# 检查是否有初始位置设置
+	call_deferred("_check_spawn_position")
+	
+	# 播放初始动画
+	if animation_player.has_animation("idle"):
+		animation_player.play("idle")
+	
+func _check_spawn_position() -> void:
+	var spawn_pos = SceneManager.get_next_scene_position()
+	if spawn_pos != null:
+		global_position = spawn_pos
+
+func _physics_process(delta: float) -> void:
+	_handle_movement(delta)
+
+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)
+	var direction := Input.get_vector(
+		"move_left", "move_right", 
+		"move_up", "move_down"
+	)
+	
+	# 应用移动
+	if direction != Vector2.ZERO:
+		velocity = direction * MOVE_SPEED
+		_update_animation_state(direction)
+	else:
+		velocity = Vector2.ZERO
+		_play_idle_animation()
+	
+	move_and_slide()
+	
+	# 发送移动事件 (如果位置发生明显变化)
+	if velocity.length() > 0:
+		EventSystem.emit_event(EventNames.PLAYER_MOVED, {
+			"position": global_position
+		})
+
+func _update_animation_state(direction: Vector2) -> void:
+	if not animation_player:
+		return
+
+	# Determine primary direction
+	if abs(direction.x) > abs(direction.y):
+		if direction.x > 0:
+			last_direction = "right"
+		else:
+			last_direction = "left"
+	else:
+		if direction.y > 0:
+			last_direction = "down"
+		else:
+			last_direction = "up"
+	
+	animation_player.play("walk_" + last_direction)
+
+func _play_idle_animation() -> void:
+	if animation_player:
+		animation_player.play("idle_" + last_direction)