fix: debounce resize and enlarge broadcast buffer for TUI resize stability

desktop/integration_test/cd_resize_test.dart

@@ -0,0 +1,91 @@
+// 专项验证：cd 跨目录 + resize 后内容不重复。
+import 'dart:typed_data';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter_alacritty/flutter_alacritty.dart';
+import 'package:integration_test/integration_test.dart';
+
+import 'package:rtty_desktop/main.dart' as app;
+import 'package:rtty_desktop/src/terminal_screen.dart';
+
+void main() {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  testWidgets('cd 跨目录 + resize 内容完整性', (WidgetTester tester) async {
+    await app.main();
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('CONNECT'));
+    await tester.pump();
+
+    // 等待连接。
+    final deadline = DateTime.now().add(const Duration(seconds: 8));
+    while (DateTime.now().isBefore(deadline)) {
+      await tester.pump(const Duration(milliseconds: 200));
+      if (find.text('AWAITING CONNECTION').evaluate().isEmpty) break;
+    }
+    expect(find.text('AWAITING CONNECTION'), findsNothing);
+
+    final engine = tester
+        .state<TerminalViewState>(find.byType(TerminalView))
+        .widget
+        .engine;
+    engine.initializeEmpty(24, 80);
+
+    void send(String s) =>
+        engine.write(Uint8List.fromList(s.codeUnits));
+
+    String gridText() {
+      final g = engine.gridForView;
+      final sb = StringBuffer();
+      for (var r = 0; r < g.rows; r++) {
+        for (var c = 0; c < g.columns; c++) {
+          final cp = g.codepointAt(r, c);
+          sb.writeCharCode(cp == 0 ? 32 : cp);
+        }
+        sb.write('\n');
+      }
+      return sb.toString();
+    }
+
+    Future<bool> waitFor(bool Function(String) pred,
+        {int secs = 6}) async {
+      final end = DateTime.now().add(Duration(seconds: secs));
+      while (DateTime.now().isBefore(end)) {
+        await tester.pump(const Duration(milliseconds: 200));
+        if (pred(gridText())) return true;
+      }
+      return pred(gridText());
+    }
+
+    // ---- 1. cd 跨目录 ----
+    final target = r'C:\Users\NianJiu\rttytest\subdir';
+    send('cd $target\r\n');
+    final cdOk = await waitFor((t) => t.contains('rttytest\\subdir'));
+    debugPrint('cd 后 prompt 含目标目录: $cdOk');
+    if (!cdOk) debugPrint('--- grid ---\n${gridText()}');
+    expect(cdOk, isTrue, reason: 'cd 到绝对路径后 prompt 应显示新目录');
+
+    // ---- 2. resize 后内容不重复 ----
+    // 记录 resize 前的非空行。
+    send('dir\r\n');
+    final beforeOk = await waitFor((t) => t.contains('subdir') && t.contains('dir'));
+    debugPrint('dir 输出: $beforeOk');
+
+    // 连续 resize 数次（模拟窗口拖动），验证内容不产生重复/错乱。
+    for (final (c, r) in [(100, 30), (120, 35), (90, 28), (110, 32)]) {
+      engine.resize(columns: c, rows: r);
+      await tester.pump(const Duration(milliseconds: 150));
+    }
+    engine.resize(columns: 100, rows: 30);
+    await tester.pump(const Duration(milliseconds: 300));
+
+    // 重置引擎网格尺寸后，发送简单命令，验证仍能正常回显（无重复错乱）。
+    send('echo RESIZE_OK\r\n');
+    final ok = await waitFor((t) => t.contains('RESIZE_OK'));
+    debugPrint('resize 后命令回显: $ok');
+    expect(ok, isTrue, reason: 'resize 后命令应正常回显且无重复');
+
+    debugPrint('--- 最终 grid ---\n${gridText()}');
+  });
+}