PR gate & preview

Intent: every change set passes through CI truth (build, unit, static checks) and, when policy demands it, a hosted preview with evidence attached to the PR or ticket.

• Red checks are blocking unless policy explicitly allows merge with waiver—and waiver is visible in the audit trail.
• Preview URLs are stable enough for reviewers; flaky infra is tracked as infra debt, not “ignored QA.”

• Required status checks on the default branch.
• Optional preview deploy workflow on PR synchronize.
• Marker pattern in PR bodies/comments so agents do not spam duplicates (see your org’s marker contract).

• Playwright — hosted regression runner role.
• Preview smoke check — lane prompt intent.
• Delivery, quality & release — gate language.