chore(ci): skip Playwright browser installation

[chenjiahan]

Use system Chrome for tests and remove the Playwright browser installation step. Local tests now require Chrome to be installed.

Measured over 8 runs per commit (7f091be → 85137ff). All 32 jobs passed. Times are medians, excluding queue time.

Metric	Before	After	Change
Windows job	58s	45.5s	−12.5s (−21.6%)
Ubuntu job	25s	24s	−1s (−4%)
Windows Run Test	3s	9s	+6s
Ubuntu Run Test	2s	7.5s	+5.5s

Removing installation saves 18s on Windows and 9s on Ubuntu, but Chrome startup offsets part of that saving. Diagnostic runs measured a 5–6s first launch on Windows; Ubuntu startup was variable.

Example runs: before, after, startup diagnosis.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-20T08:43:54.246593Z	85137ff	PR opened

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[chenjiahan]

Closing: Windows CI saves 12.5s (21.6%), but Ubuntu is roughly unchanged. Chrome's cold startup offsets part of the installation savings.

For a reusable template, this benefit does not justify requiring Chrome locally and allowing browser versions to differ across environments. Keeping Playwright's version-matched browser is more reproducible.

A possible follow-up is pnpm exec playwright install chromium --only-shell to reduce downloads while keeping the default browser. This has not been benchmarked.