fix(cli): hide Windows daemon consoles

[Simon Knott (Skn0tt)]

Fixes #42152. This fix is scoped to CLI and MCP and /taskkill, so compared to #38776 it should have a much smaller blast radius. In my testing the cli open --headed and cli show commands still worked fine across CMD and PowerShell.

Two constraints that might limit our risk appetite here:

• this only helps CMD users, PowerShell was already fine in my testing
• npx has the same bug, so anybody who uses us through npx won't see an improvement

[github-actions]

Test results for "tests 1"

5 flaky

⚠️ [chromium-library] › library/browsercontext-page-event.spec.ts:173 › should work with Ctrl-clicking `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/chromium/chromium.spec.ts:299 › should report intercepted service worker requests in HAR `@realtime-time-library-chromium-linux`
⚠️ [chromium-library] › library/video.spec.ts:113 › screencast › should capture static page `@chromium-ubuntu-22.04-node22`
⚠️ [chromium-library] › library/video.spec.ts:699 › screencast › should capture full viewport on hidpi `@chromium-ubuntu-22.04-node22`
⚠️ [firefox-page] › page/page-event-request.spec.ts:181 › should return response body when Cross-Origin-Opener-Policy is set `@firefox-ubuntu-22.04-node20`

51234 passed, 1190 skipped

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Merge workflow run.

[github-actions]

Test results for "MCP"

1 failed
❌ [firefox] › mcp/cli-core.spec.ts:57 › click link @mcp-windows-latest-firefox

8049 passed, 1284 skipped

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Merge workflow run.

[github-actions]

🟢 CI is clear — the one failure is a pre-existing Windows-Firefox flake

Hi, I'm the Playwright bot and I took a first look at the CI failures here.

The only real failure is [firefox] › mcp/cli-core.spec.ts:57 › click link on mcp-windows-latest-firefox, and it's a known flake, not something this PR broke. Everything else is flaky/interrupted, which isn't triage-worthy. This PR looks clear.

Details

Overall: no failure traces back to this change. The diff is a small, Windows-only windowsHide: true addition to a few spawn/spawnSync calls, and it doesn't alter the behavior the failing test asserts on.

Pre-existing flake / infra

• [firefox] › mcp/cli-core.spec.ts:57 › click link (@mcp-windows-latest-firefox) — pre-existing flake, scoped to Windows Firefox. Across the test-results DB this test failed 12 of 418 runs (2.9%) on mcp-windows-latest-firefox, and passed the other 406, while it's 0 failures in 660 runs on mcp-ubuntu-latest-firefox and 0 in 657 on mcp-macos-latest-firefox. The failures land on plenty of SHAs this PR can't be responsible for — release-1.62, roll-into-pw-chromium/1237 (feat(chromium): roll to r1237 #42072), test(page): cover file URL to about:blank navigation #42053, chore: mark v1.62.1 #42020, fix(aria): preserve names from collapsed text contributors #41988, fix(mcp): reconnect to the browser after disconnect #41966, chore(recorder): unify action coalescing and simplify action types #41958, and more. Same test, same bot, unrelated branches → flake, not a regression.

Not triage-worthy

• The "tests 1" report is 5 flaky, 0 failed — nothing to look at (browsercontext-page-event.spec.ts:173, chromium.spec.ts:299, video.spec.ts:113 & :699, page-event-request.spec.ts:181, all passed on retry).

_{Triaged by the Playwright bot - agent run}