The parallel design session settled the tombstoned-ancestor question:
a card counts as trashed if its own flag or its lane's says so, so
tombstoning a lane ejects its cards from a live selection — they render
nowhere once the lane collapses to a single trash entry, and nothing
invisible may stay selected, drag-included, or pending-cut. One-line
predicate change in Selection.resolved(against:), plus the test.
Full BoardStore suite green (15 tests).
Claude-Session: https://claude.ai/code/session_018BjQRYBR6jQja3jCRi5S3A