chore: retrigger Vercel preview deployment

The preview deploy for 59931e6 failed on Vercel's side while all 15
GitHub checks passed. The docs build graph is {@objectstack/docs,
@objectstack/spec} — zero overlap with this branch's packages — and the
commit touches no package.json/lockfile, so the failure cannot originate
here (`turbo run build --filter=@objectstack/docs --force` passes
locally). Vercel posts a commit status rather than a check run, so a new
commit is the only way to retrigger the deployment.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: os-zhuang