skills(pm-dispatch): a Seam: card routes by the seam — spec seat, vertical dispatch by default; rule 2 splits a spec↔objectui seam into parent + per-repo sub-issues

skills(pm-dispatch): a Seam: card routes by the seam — spec seat, vertical dispatch by default; rule 2 splits a spec↔objectui seam into parent + per-repo sub-issues #12202