feat: 添加游戏启动界面和着色器效果

- 新增启动界面背景和logo
- 实现顶部和底部阴影着色器
- 添加难度选择滑块和角色名输入框
- 优化多人游戏按钮交互
- 修复编译提示面板的动画效果
- 更新UI主题样式

scripts/Tools/Managers/CameraManager.gd

@@ -19,6 +19,7 @@ func _physics_process(_delta):
 		offset += ((get_global_mouse_position() - UIState.player.position).clampf(-100, 100) - offset) * 0.15
 
 static func shake(millseconds: float, intensity: float = 10, steper: Callable = func(currentValue, _totalValue, _restPercent): return currentValue):
+	if StarterPanel.buildingShader: return
 	var startTime = WorldManager.getTime()
 	instance.shakeIntensity = intensity
 	await TickTool.until(