perf(ci): build sandbox preview in parallel with storybook

[Han5991]

Summary

The PR build job is a single ~6.5min pipeline, and one step dominates it: the sandbox Next.js export (4m15s of it, per recent run timings). Everything else in the job — core build, four typechecks, storybook build, PR analysis — fits in ~2min. This PR moves the sandbox export into its own job so it runs in parallel instead of serializing after everything else.

PR CI wall time for component PRs drops from ~8–9min to ~6.5min, and the a11y audit starts ~4min earlier. Cost: one extra runner spin-up plus a duplicated ~40s core build.

Changes

• build-storybook (renamed from build): core build + typechecks + storybook + PR analysis (~2min). Uploads the storybook + analysis artifacts and carries the preview-URL outputs, as before.
• build-sandbox (new): core build + sandbox export with the pinned Next.js cache, PR-only, parallel from t0 (~5min). The no-restore-keys cache rationale (feat: XDS un-prefix migration — bare names canonical, XDS* compat aliases #2941) is unchanged.
• build (new join gate): keeps the historical check name so anything keyed on "build" being green — branch protection, tooling, habit — keeps working. Fails if either parallel build fails; passes when build-sandbox is legitimately skipped (docsite-only PRs); skips when build-storybook skips (merge_group), matching the old cascade behavior.
• pr-a11y now depends only on build-storybook, so it starts as soon as the storybook artifact exists (~2min) instead of waiting for the sandbox too.
• pr-comment now also waits for deploy-preview pr-comment-update gained an explicit needs: pr-comment — correction (post-review): these two jobs live in pr-comment.yml (a separate workflow_run workflow this PR does not touch); the bullets described a considered change that didn't ship. The shipped diff is ci.yml only.

Behavior parity

Scenario	Before	After
Normal PR, sandbox build fails	build red	build red (via join)
Docsite-only PR	build green (steps skipped)	build green (sandbox skipped, join passes)
Fork PR	previews/comments skipped	unchanged (builds still run, deploy/comment jobs skip)
merge_group	build skipped (cascade from check-scope)	join skipped the same way

Test plan

• YAML parses; full needs-graph reviewed; no leftover needs.build.* references (grep-verified)
• Scenario walkthrough above (normal / docsite-only / fork / merge_group / partial failure)
• This PR's own CI run executes the modified ci.yml — the Checks tab shows the new graph and timings live

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Project	Deployment	Actions	Updated (UTC)
astryx	Ready	Preview, Comment	Jul 12, 2026 1:41am

[github-actions]

PR Analysis Report

No new or modified components detected.

Bundle Size Summary

Package	Size (ESM)	Size (CJS)	Gzipped
@astryxdesign/core	N/A	4.6KB	0B

Accessibility Audit

Status: No accessibility violations detected.

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_{Generated by PR Enrichment workflow | View full report}

[cixzhang]

🟢 No review blockers found — CI-only change, verified clean within what I can check.

Initial review pass (community contributor) — findings are a triage map for maintainers, not a verdict.

This splits the ~4min sandbox export out of the build job into a parallel build-sandbox job and folds both back through a build join gate that keeps the historical check name.

Verified:

• build-storybook (renamed from build) retains all four consumed outputs (pr_number, short_hash, storybook_url, sandbox_url); no downstream job references a now-removed needs.build.* output.
• The build join gate handles the edge cases correctly: docsite-only PRs skip build-sandbox and the gate still passes (success|skipped), and a skipped build-storybook (merge_group) skips the gate — matching the previous single-job cascade.
• pr-a11y and deploy-preview now point at the right upstream jobs for their artifacts.

Minor (non-blocking): the PR description mentions pr-comment/pr-comment-update reordering, but those jobs live in a separate workflow_run file that isn't touched here — the description slightly overstates the diff. No code impact.

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Recap — #3811 · perf(ci): build sandbox preview in parallel with storybook · @Han5991
What it does: runs the slow sandbox export in its own job so PR CI wall time drops from ~8–9min to ~6.5min, with a join gate preserving the build check name.
Recommendation: Approve.