fix(ci): increase login goto timeout to 120s and fix role switcher skip

- Increase page.goto timeout from 60s to 120s in all login helpers
  (9 CI timeout failures were all login page.goto timeouts)
- Make clazz-supervisor-matrix switchToRole gracefully skip when
  role switcher icon is not available (no multi-role user)
- Update clazz-scheduling tests to match production UI (no
  .fc-createClazz-button, use .view-toolbar instead)
- Update clazz-ui .fc-toolbar → .view-toolbar selector
- Update department test to handle single-dept optional
  CurrentDepartmentId (multi-org user may not auto-select)
- Update teacher-switching tests to match student profile UI
  (no .current-teacher section)

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

CLAUDE.md

@@ -14,6 +14,17 @@
 - 不道歉，不冗余收尾
 - 引用代码时用真实文件路径
 
+## E2E 测试失败/跳过修复原则
+
+当 E2E 测试出现 `failed` 或 `skipped` 时，**必须先判断是测试 outdated 还是 case 确实测出了 bug**，再决定修复方案：
+
+- **测试 outdated**（选择器不存在、UI 已变更、流程已改）→ 更新测试以匹配当前 UI/API 行为
+- **真实 bug**（测试断言暴露了代码缺陷）→ 修复业务代码
+- **数据依赖 skip**（无排课数据、无事件等）→ 保留动态 skip 逻辑，确保有数据时不跳过
+- **会话 flake**（登录态丢失、机构页未渲染）→ 保留 skip 兜底，但检查是否有可改进的等待策略
+
+不要盲目删除 failing test 或把 failing test 改成 skip。每条 skip/fail 都要有明确理由。
+
 ## 工具链
 
 - 文本检索：`rg`（ripgrep）