maintenance: investigate persistent Netlify deploy-preview failures

[happy-haki]

Context

The Netlify semantic-template deploy preview has failed repeatedly on open dependency PRs #189, #190, #191, and #192. The failures include the Header rules, Pages changed, and Redirect rules checks, while older PRs have passed the same checks.

Evidence

• chore(deps): update dependency shiki to v4.4.3 #189: chore(deps): update dependency shiki to v4.4.3 #189
• chore(deps): update dependency ultracite to v7.10.6 #190: chore(deps): update dependency ultracite to v7.10.6 #190
• chore(deps): update dependency postcss to v8.5.26 #191: chore(deps): update dependency postcss to v8.5.26 #191
• chore(deps): update dependency @types/node to v26.2.0 #192: chore(deps): update dependency @types/node to v26.2.0 #192
• Latest failed deploy example: https://app.netlify.com/projects/semantic-template/deploys/6a767a3bc6a0250008044a7a

Requested follow-up

Inspect Netlify deploy diagnostics/project configuration and restore reliable preview validation. Do not merge the affected PRs while required preview checks remain failed.

[happy-haki]

Daily maintainer check (2026-08-14): Netlify deploy-preview failures remain on PRs #152 (biome), #169 (typescript), #190 (ultracite). PRs #191, #192, #189, #184 passed Netlify — suggesting the failures are not a universal Netlify outage but may be specific to the build changes in those branches. Recommended next step: compare the failing deploy logs to identify whether the root cause is a Netlify build plugin, the dependency change itself, or a Netlify configuration drift.

[happy-haki]

Daily maintainer check (2026-09-03): new evidence narrows the root cause.

Latest data points:

• 2026-09-02: PRs chore(deps): update pnpm to v11.25.0 #208 (pnpm) and chore(deps): lock file maintenance #207 (lock file maintenance) passed all Netlify preview checks; PR fix(deps): update nextjs monorepo to v16.3.4 - autoclosed #199 (next 16.3.4) failed all three, merged minutes apart from the passing ones.
• 2026-08-30: chore(deps): update dependency ultracite to v7.10.7 #205 (ultracite) and chore(deps): update dependency lint-staged to v17.4.1 #206 (lint-staged) failed all three despite trivial, unrelated diffs.
• 2026-09-03: chore(deps): update dependency @types/node to v26.4.1 #209 (@types/node patch, types-only) failed all three, while local pnpm install --frozen-lockfile and pnpm build (next build → BUILD_ID FINQVTcy8OO_vKaBhhOv7) pass on the same branch.

Reading: failures correlate with neither dependency content nor branch — trivial type-only and dev-tool bumps fail while larger PRs pass, sometimes minutes apart. This points to the Netlify side (project config/plugin/deploy queue), not the PR builds.

Baseline note: pnpm lint (ultracite check) currently fails on main with pre-existing findings (useSortedKeys assists, noJsxPropsBind, etc.) — unrelated to Netlify but worth a separate cleanup pass.

Blocker: root-cause confirmation needs Netlify project console access (deploy logs, build plugins, header/redirect rules config) which is not available from the GitHub API. Suggest checking https://app.netlify.com/projects/semantic-template deploy logs for one failing vs one passing deploy from 2026-09-02 00:33 UTC.

Keeping this issue open; dependency PRs continue to be evaluated individually (Netlify checks are not required by the semantic-main-brach ruleset).

[happy-haki]

Daily maintainer check 2026-09-05: Netlify deploy-preview still failing on all three open PRs (#210, #211, #169-branch) while labeler (GitHub Actions) is green — same content-independent pattern. Both #210 and #211 passed full local gates (install/lint-delta-0/build) and were merged per the #204/#205/#206/#209 precedent. No Netlify-side diagnostics accessible without the Netlify account; root-cause investigation remains blocked on that access.

[happy-haki]

Daily maintainer check 2026-09-06: further evidence for the content-independent pattern.

Today's data (all within ~30 min):

• ✅ PASS: chore(deps): update dependency postcss to v8.5.28 #212 (postcss 8.5.26→8.5.28, runtime CSS processor) — full deploy preview ready
• ❌ FAIL: chore(deps): update dependency ultracite to v7.10.8 #213 (ultracite 7.10.7→7.10.8, dev-only linter, zero runtime impact) — all 3 checks failed
• ✅ PASS: chore(deps): update tailwindcss monorepo to v4.3.3 #218 (tailwindcss monorepo 4.3.2→4.3.3, larger lockfile surface than chore(deps): update dependency ultracite to v7.10.8 #213) — deploy preview ready
• ❌ FAIL: chore(deps): update dependency typescript to v7 #169 (unchanged branch, no new commits)
• ✅ PASS (yesterday, still open): chore(deps): update typescript to v7 (tsconfig baseUrl migration) #214 preview

A trivial devDependency patch failed while two runtime-affecting bumps with much larger lockfile diffs passed minutes apart. This is inconsistent with any content-based root cause; continues to point at the Netlify project/build-infrastructure side. #213 and #218 were merged on documented local gates (install/lint-delta-0/build) per the #204–#211 precedent. Root-cause investigation still blocked on Netlify console access.