A file-upload / processing indicator sourced from the real hot-glass gather-and-marver sequence: an off-centre blob rolls back and forth on a flat baseline, losing its lumps a little more with every roll pass while it spins continuously underneath, the correction visibly progressing rather than a generic spinner or indeterminate ring.
npx shadcn@latest add https://design.helpmarq.com/r/gather-marver.jsongather-marver