Runs @next/bundle-analyzer on PRs and diffs per-route First Load JS
against the cached master baseline. Posts a sticky PR comment and
fails the job if any route exceeds the budget configured in
apps/studio/package.json#nextBundleAnalysis.
Motivation: a recent PR pulled the AI Assistant graph into the global
HelpPanel chunk, bloating every route and OOM-ing Vercel builds. The
existing CI (unit tests, e2e, typecheck, lint) wouldn't have caught
that because nothing diffs bundle sizes pre-merge.
The budget value is a placeholder; calibrate from a real master build
once this lands.