Add teacher microphone and per-question model selection

tests/e2e/teacher-reply-layout.spec.ts

@@ -189,3 +189,20 @@ for (const width of [319, 508]) for (const kind of ['ordinary', 'ideas', 'struct
     expect(errors).toEqual([]);
   });
 }
+
+for (const width of [319, 508]) test(`teacher model selector and microphone fit the composer at ${width}px`, async ({ page }) => {
+  await page.goto(`${url}?kind=rich-text&width=${width}`);
+  const panel = page.getByTestId('teacher-chat-panel');
+  const input = page.getByRole('textbox', { name: '向智能体提问' });
+  await input.fill('语音和选模测试草稿');
+  await panel.getByRole('button', { name: /老师模型/ }).click();
+  await page.getByRole('menuitemradio', { name: 'test-second-model' }).click();
+  await expect(input).toHaveValue('语音和选模测试草稿');
+  await expect(panel.getByRole('button', { name: '语音输入' })).toBeVisible();
+  expect(await panel.evaluate(el => el.scrollWidth <= el.clientWidth)).toBe(true);
+  const controls = panel.getByTestId('teacher-composer-runtime-controls');
+  expect(await controls.evaluate(el => el.scrollWidth <= el.clientWidth)).toBe(true);
+  await panel.screenshot({ path: test.info().outputPath(`teacher-composer-${width}.png`) });
+  await panel.getByRole('button', { name: '提问', exact: true }).click();
+  expect(await page.evaluate(() => (window as unknown as { __teacherReplyInputs: Array<{modelId?: string}> }).__teacherReplyInputs.at(-1)?.modelId)).toBe('test-second-model');
+});