fix(clazz-e2e): increase role dialog wait in clazz-ui.spec.ts to 15s

Same fix as e43b059: the 3-second waitForTimeout before checking the
role selection dialog is insufficient in CI. Replaced with
waitFor({ state: 'visible', timeout: 15_000 }).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/clazz-ui.spec.ts

@@ -32,11 +32,11 @@ test.describe('排课页面 UI', () => {
     const q = new URLSearchParams({ unionid: moicenUnionid, status: '2' });
     await page.goto(`/?${q.toString()}`, { waitUntil: 'domcontentloaded', timeout: 60_000 });
     await expect(page.locator('#app')).toBeVisible({ timeout: 60_000 });
-    await page.waitForTimeout(3000);
 
-    // 选择身份（如果弹出）
+    // 等待身份选择弹窗（最多 15 秒）
     const rs = page.getByText('请选择您的登录身份');
-    if (await rs.isVisible().catch(() => false)) {
+    try {
+      await rs.waitFor({ state: 'visible', timeout: 15_000 });
       const items = page.locator('.van-grid-item');
       const count = await items.count();
       // items[0]=测试员, items[1]=学生, items[2]=教师
@@ -46,6 +46,8 @@ test.describe('排课页面 UI', () => {
         await items.first().click();
       }
       await page.waitForTimeout(3000);
+    } catch {
+      // 无弹窗 — 已有身份
     }
 
     // 导航到排课页面