chore：完善项目目录结构和基础框架

- 添加核心系统框架目录结构
- 创建游戏模块化组织架构
- 添加数据配置和本地化支持
- 建立脚本分类管理体系
- 创建场景预制件管理目录

core/managers/GameManager.gd

@@ -0,0 +1,50 @@
+extends Node
+
+# 游戏管理器 - 全局游戏状态管理
+# 单例模式，管理游戏的整体状态和生命周期
+
+signal game_state_changed(new_state: GameState)
+
+enum GameState {
+	LOADING,    # 加载中
+	AUTH,       # 认证状态
+	MAIN_MENU,  # 主菜单
+	IN_GAME,    # 游戏中
+	PAUSED,     # 暂停
+	SETTINGS    # 设置
+}
+
+var current_state: GameState = GameState.LOADING
+var previous_state: GameState = GameState.LOADING
+var current_user: String = ""
+var game_version: String = "1.0.0"
+
+func _ready():
+	print("GameManager 初始化完成")
+	change_state(GameState.AUTH)
+
+func change_state(new_state: GameState):
+	if current_state == new_state:
+		return
+	
+	previous_state = current_state
+	current_state = new_state
+	
+	print("游戏状态变更: ", GameState.keys()[previous_state], " -> ", GameState.keys()[current_state])
+	game_state_changed.emit(new_state)
+
+func get_current_state() -> GameState:
+	return current_state
+
+func get_previous_state() -> GameState:
+	return previous_state
+
+func set_current_user(username: String):
+	current_user = username
+	print("当前用户设置为: ", username)
+
+func get_current_user() -> String:
+	return current_user
+
+func is_user_logged_in() -> bool:
+	return not current_user.is_empty()