The second half: system drag sessions over phase 1's model, per
DRAG-REORDER.md and 04-interactions.md § Drag & drop.
- Card faces, lane headers, and trash rows drag as NSItemProvider sessions
(two exported UTTypes, JSON payload in flatten order, plain-text titles as
the secondary representation) — replacing m4's custom lane-reorder gesture
and trash drag-out wholesale; the app-wide DragSession carries the members,
the frozen dragged sizes, the live proposal, and the effective operation.
- Three drop delegates (lane masonry, strip, window fallback), each accepting
both types and routing internally per the single-target-dispatch rule; the
cursor is the physical mouse converted to strip space; proposals come from
DropSlotMath with hysteresis threaded through, and the lane-strip proposal
clamps in front of the shown trash.
- Locality picks the default — move within a board, copy across, the badge
tracking live; ⌥ forces copy (ignored on within-board lane drags), ⌘
forces move; trash rows restore within their board (positional), copy out
across boards by default, ⌘ forcing the true restore-move.
- N contiguous shadows with reflow keyed on the proposal; the
committed-overlay hold renders the dropped arrangement until the reload
echo lands (1.5 s dissolution deadline for refused writes); the
re-grounding trio: geometry re-derives per render, proposals re-validate
by liveness at release, an emptied drag cancels itself.
- Edge autoscroll (ticking driver over DragAutoScrollMath, re-targeting per
step), the mouse-up-gated late-event cleanup, and the polling watchdog —
the pathfinder's lifecycle traps, ported.
- Store: moveLanes and multi-card restoreByDrag join the one-bracket drop
commits.
784 unit tests.
Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY
