test(libs): add xterm-terminal smoke tests

4 tests covering XtermOptions construction/setters and TerminalInstance
mount/onReady/writeAll/clear/destroy lifecycle under happy-dom.

libs/xterm-terminal/src/__tests__/terminal.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, it } from 'vitest';
+import { TerminalInstance, XtermOptions } from '../terminal';
+
+describe('XtermOptions', () => {
+  it('可无参构造，字段全部 undefined', () => {
+    const opts = new XtermOptions();
+    expect(opts.theme).toBeUndefined();
+    expect(opts.fontFamily).toBeUndefined();
+    expect(opts.fontSize).toBeUndefined();
+    expect(opts.onReady).toBeUndefined();
+  });
+
+  it('可设置字段', () => {
+    const opts = new XtermOptions();
+    opts.theme = 'dark';
+    opts.fontSize = 14;
+    expect(opts.theme).toBe('dark');
+    expect(opts.fontSize).toBe(14);
+  });
+});
+
+describe('TerminalInstance', () => {
+  it('挂载到容器并触发 onReady', () => {
+    const container = document.createElement('div');
+    let ready = false;
+    const opts = new XtermOptions();
+    opts.onReady = () => {
+      ready = true;
+    };
+
+    const inst = new TerminalInstance(container, opts);
+    expect(ready).toBe(true);
+
+    // xterm.js 在容器内创建 .xterm 元素
+    expect(container.querySelector('.xterm')).toBeTruthy();
+
+    inst.destroy();
+  });
+
+  it('writeAll 清屏后重写 stdout + stderr', () => {
+    const container = document.createElement('div');
+    const inst = new TerminalInstance(container, new XtermOptions());
+
+    // 不报错即通过（xterm.js 在 happy-dom 下 write 是 no-op 渲染）
+    inst.writeAll('hello\n', 'error\n');
+    inst.clear();
+
+    inst.destroy();
+  });
+});