[KillianLucas]

What changed

• build the pinned Playwright runtime before verification
• build both Playwriter and the extension on every PR and main/codex push
• run the full browser/relay suite without snapshot auto-updates
• serialize Chrome integration files to avoid shared-port collisions
• replace two third-party-site-dependent assertions with local deterministic fixtures

Verified

• Node 22.12 + pnpm 10.18.1 frozen install
• full build
• 20 test files: 221 passed, 1 intentionally skipped