存档重构，游戏内容解锁机制；教程完善（未完成）

Assets/Scripts/UI/Elements/SelectionBoxUIPage.cs

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+using System.Collections.Generic;
+using Ichni.UI;
+using UnityEngine;
+
+namespace Ichni.Menu.UI
+{
+    /// <summary>
+    /// 通用 SelectionBox 的页面宿主，职责等同于 MessageBox 的页面容器：
+    /// 显示时动态生成一个 SelectionBox，选择完成后统一淡出并销毁本次实例。
+    /// </summary>
+    public class SelectionBoxUIPage : UIPageBase
+    {
+        [Header("Selection Box Page")]
+        public SelectionBox selectionBoxPrefab;
+        public RectTransform selectionBoxContainer;
+
+        private SelectionBox _currentSelectionBox;
+        private bool _isShowing;
+
+        /// <summary>当前是否已有一个 SelectionBox 等待玩家选择。</summary>
+        public bool IsShowing => _isShowing;
+
+        /// <summary>
+        /// 生成并显示一组运行时选项。页面显示期间拒绝重复请求，避免两个弹窗争夺输入。
+        /// </summary>
+        public bool Show(string title, string content, IReadOnlyList<SelectionBoxOption> options)
+        {
+            if (_isShowing)
+            {
+                Debug.LogWarning("[SelectionBoxUIPage] 已有 SelectionBox 显示中，忽略重复请求。");
+                return false;
+            }
+
+            if (mainCanvasGroup == null || selectionBoxPrefab == null || selectionBoxContainer == null)
+            {
+                Debug.LogWarning("[SelectionBoxUIPage] 缺少 CanvasGroup、SelectionBox Prefab 或容器，无法显示选项框。");
+                return false;
+            }
+
+            _currentSelectionBox = Instantiate(selectionBoxPrefab, selectionBoxContainer);
+            _currentSelectionBox.Closed += HandleSelectionBoxClosed;
+            if (!_currentSelectionBox.SetUp(title, content, options))
+            {
+                Destroy(_currentSelectionBox.gameObject);
+                _currentSelectionBox = null;
+                return false;
+            }
+
+            _isShowing = true;
+
+            // UIPageBase 默认淡入完成后才开启射线；选择框从出现瞬间就必须阻断底层输入。
+            mainCanvasGroup.gameObject.SetActive(true);
+            mainCanvasGroup.interactable = true;
+            mainCanvasGroup.blocksRaycasts = true;
+            FadeIn();
+            return true;
+        }
+
+        private void HandleSelectionBoxClosed(SelectionBox selectionBox)
+        {
+            if (selectionBox != _currentSelectionBox) return;
+
+            FadeOut(0.2f, false, () =>
+            {
+                if (_currentSelectionBox != null)
+                    Destroy(_currentSelectionBox.gameObject);
+
+                _currentSelectionBox = null;
+                _isShowing = false;
+            });
+        }
+    }
+}