feat: buffer terminal input sequences

- add stdin buffer for escape sequences and bracketed paste

- parse control keys and CSI modifier combinations

- simplify example to focus on interactive components

src/Example/Program.cs

@@ -19,18 +19,9 @@ var done = new ManualResetEventSlim();
 var eventsText = new Text("最近事件:\n- 无");
 var statusText = new Text();
 var loader = new Loader(textMeasurer) { Message = "运行中" };
-var selectPreview = new SelectList(textMeasurer) { Height = 4 };
-var markdownPreview = new Markdown(
-    "# Markdown 预览\n" +
-    "## 二级标题会转成大写\n" +
-    "- 列表项会转成星号前缀\n" +
-    "> 引用会转成竖线前缀\n" +
-    "支持 **粗体标记清理** 和 `行内代码标记清理`");
 using var loaderCancellation = new CancellationTokenSource();
 var input = new TinyTUI.Components.Input(textMeasurer) { Prompt = "请输入: " };
 
-selectPreview.SetItems(["Text", "Input", "Editor", "SelectList", "Markdown", "Loader", "Overlay"]);
-
 input.OnChanged = value => UpdateStatus(statusText, value, textMeasurer, renderer);
 input.OnSubmitted = value =>
 {
@@ -67,9 +58,8 @@ AddAll(
     page,
     new Text("TinyTUI 基础组件示例"),
     new Text("======================"),
-    new Markdown(
-        "# 操作说明\n" +
-        "- Markdown Loader SelectList 预览会在页面启动时直接显示\n" +
+    new Text(
+        "操作说明\n" +
         "- 输入文本后 Enter 提交\n" +
         "- /help 打开帮助弹层\n" +
         "- /select 打开可交互选择列表\n" +
@@ -78,13 +68,7 @@ AddAll(
     new Text(),
     new Box(statusText, textMeasurer) { Title = "状态" },
     new Text(),
-    new Box(markdownPreview, textMeasurer) { Title = "Markdown 预览" },
-    new Text(),
-    new Box(loader, textMeasurer) { Title = "Loader" },
-    new Text(),
-    new Box(selectPreview, textMeasurer) { Title = "SelectList 预览" },
-    new Text(),
-    new Box(input, textMeasurer) { Title = "Input" },
+    new Box(new Container { Children = { loader, input } }, textMeasurer) { Title = "Input" },
     new Text(),
     new Box(eventsText, textMeasurer) { Title = "事件" });
 
@@ -160,8 +144,8 @@ static void AddAll(Container container, params IComponent[] components)
 file sealed class HelpOverlay(ITuiRuntime runtime, ITextMeasurer textMeasurer) : IInputComponent
 {
     private readonly Box _box = new(
-        new Markdown(
-            "# Overlay 示例\n" +
+        new Text(
+            "Overlay 示例\n" +
             "\n" +
             "- 这个弹层由 Runtime 显示\n" +
             "- OverlayManager 会把它合成到基础页面上\n" +