The pathfinder's drag-reorder model, ported and generalized (DRAG-REORDER.md
travels with it, rewritten for lanes, the interior masonry, multi-drag,
cross-board sessions, the re-grounding trio, and the committed-overlay hold):
- DropSlotMath — resting-layout zones from analytic lane arithmetic and the
pure masonry placement (MasonryLayout now lays out through the same
MasonryPlacement the drag reads, so geometry cannot drift), span-capped
triggers sized to the dragged run's future footprint, hysteresis holds with
the fresh-entry fallback, boundary ties, own-slot no-ops; nil means hold.
- DragAutoScrollMath — the activation bands and velocity ramp, pure.
- The drop commits, one performWrite bracket each: moveCards/copyCards within
a board (insertion ranks touch only the dragged cards; renumber fallback);
receiveCards/receiveLanes/receiveRestoredCards on the destination store for
cross-board copy and ⌘-move with the import-boundary remint, lane copies
stripping tombstoned cards while moves carry them; restoreByDrag is now
positional, writing order only when the drop names a new one.
Gestures, sessions, previews, and delegates are the second half.
773 unit tests (87 new since the keyboard grammar).
Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY
