项目 5 补齐：旧版线程 API（Suspend / Resume / Abort）与 ListBox

- 编译时把 Thread 的 Suspend / Resume / Abort、ThreadState、Sleep、new Thread 改写成平台的
  协作式实现：被挂起或终止的线程在 Sleep、后台改控件、调设备类库、弹提示框时停下或结束；
  ThreadStateException 等行为与 .NET Framework 一致；编辑器不再提示"已过时"
- ListBox：列表项、单选、SelectedIndexChanged 先于 Click、删除选中项后取消选中；
  ComboBox 与 ListBox 共用 ListControl 和列表项集合；设计器工具箱加"列表框"
- 评分规则的"包含"对列表框检查所有列表项
- 示例：项目 5 任务 2（烟雾，线程）、任务 3（推送灾情，二维数组、两个窗体、ListBox），
  参考答案修正书上直接 Abort 挂起线程、烟雾记成"发现火情"的问题
- 一直不换行的 Console 输出攒满 4096 字符先发出，避免占满内存
- 测试：旧版线程 API、ListBox 事件顺序、两个示例的端到端和评分测试

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

runtime/Sim.WinForms/Forms/ListControl.cs

@@ -0,0 +1,114 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace System.Windows.Forms;
+
+/// <summary>ComboBox 和 ListBox 的共同基类：列表项、选中项</summary>
+public abstract class ListControl : Control
+{
+    /// <summary>选中项的序号。列表项增删时直接调整（和 WinForms 一样不触发 SelectedIndexChanged）</summary>
+    private protected int SelectedIndexValue = -1;
+
+    public abstract int SelectedIndex { get; set; }
+
+    public string DisplayMember { get; set; } = "";
+    public string ValueMember { get; set; } = "";
+
+    public event EventHandler? SelectedValueChanged;
+
+    protected virtual void OnSelectedValueChanged(EventArgs e) => SelectedValueChanged?.Invoke(this, e);
+
+    public string GetItemText(object? item) => item?.ToString() ?? "";
+
+    /// <summary>列表项变化后调用：把新的列表和选中项发给浏览器</summary>
+    internal abstract void ItemsChanged();
+
+    /// <summary>Items.Clear() 时调用：先取消选中，再刷新列表</summary>
+    internal abstract void ItemsCleared();
+
+    internal void ItemInserted(int index)
+    {
+        if (SelectedIndexValue >= index) SelectedIndexValue++;
+        ItemsChanged();
+    }
+
+    /// <summary>删掉的正是选中项时取消选中，删掉前面的项时选中项序号前移</summary>
+    internal void ItemRemoved(int index)
+    {
+        if (SelectedIndexValue == index) SelectedIndexValue = -1;
+        else if (SelectedIndexValue > index) SelectedIndexValue--;
+        ItemsChanged();
+    }
+
+    protected string[] ItemTexts(IEnumerable<object?> items) => items.Select(GetItemText).ToArray();
+}
+
+/// <summary>ComboBox.ObjectCollection 和 ListBox.ObjectCollection 共用的实现</summary>
+public abstract class ListItemCollection : IList, IEnumerable<object?>
+{
+    private readonly List<object?> _items = new();
+    private readonly ListControl _owner;
+
+    private protected ListItemCollection(ListControl owner) => _owner = owner;
+
+    public int Count => _items.Count;
+    public bool IsReadOnly => false;
+    bool IList.IsFixedSize => false;
+    bool ICollection.IsSynchronized => false;
+    object ICollection.SyncRoot => this;
+
+    public object? this[int index]
+    {
+        get => _items[index];
+        set
+        {
+            _items[index] = value;
+            _owner.ItemsChanged();
+        }
+    }
+
+    public int Add(object? item)
+    {
+        if (item == null) throw new ArgumentNullException(nameof(item), "值不能为 null。");
+        _items.Add(item);
+        _owner.ItemsChanged();
+        return _items.Count - 1;
+    }
+
+    public void AddRange(object[] items)
+    {
+        _items.AddRange(items);
+        _owner.ItemsChanged();
+    }
+
+    public void Insert(int index, object? item)
+    {
+        _items.Insert(index, item);
+        _owner.ItemInserted(index);
+    }
+
+    public void Remove(object? item)
+    {
+        var index = _items.IndexOf(item);
+        if (index >= 0) RemoveAt(index);
+    }
+
+    public void RemoveAt(int index)
+    {
+        _items.RemoveAt(index);
+        _owner.ItemRemoved(index);
+    }
+
+    public void Clear()
+    {
+        _items.Clear();
+        _owner.ItemsCleared();
+    }
+
+    public bool Contains(object? item) => _items.Contains(item);
+    public int IndexOf(object? item) => _items.IndexOf(item);
+    public void CopyTo(Array array, int index) => ((ICollection)_items).CopyTo(array, index);
+    public IEnumerator<object?> GetEnumerator() => _items.GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+}