build(frontend): rebuild static/ on the merged tip (#2656)

    One build on the tip after merging dev, per the branch'"'"'s standing rule
    that intermediate commits carry a stale bundle and only the tip has to be
    right.

    dev'"'"'s CSS moved to index-Db2rfQf-.css while this branch was out; the
    rebuild lands on the same hash, so static/index.html differs from dev by
    the script line alone again.