Windows CI: iOS Simulator cancellation test never observes build start

PR #4146 在 head 95eeda0fa 的 Windows 2/2 出现基线测试失败：https://github.com/makecindy/cindy/actions/runs/34309831415/job/102334019837

`ios-simulator.test.ts` 用例 `cancels an active build before detaching and releasing scheduler capacity` 第6778行等待 build 调用一次，实际0次。Desktop 分片其余16881项通过、44项跳过。实现与测试相对 upstream/main 无差异，本 PR 未修改该模块。

需在 Windows 核查构建前置异步链及测试等待条件，保持取消后释放容量的断言，不弱化用例。当前 macOS 定向检查与 Windows 重跑分别记录在 PR #4146；已成功触发同一 head 的第2次 failed-jobs 重跑。

Start in ios-simulator.test.ts at the `cancels an active build before detaching and releasing scheduler capacity` test around line 6778, then compare the Windows failure from PR #4146 with the macOS check. Trace the build-start prerequisite and test wait condition on Windows. Done means the test observes the build, preserves the cancellation and scheduler-capacity assertions, and passes on a Windows rerun.

Written by the indexing model from the issue text.