A lane folds to a fixed slim vertical strip carrying its glyph, its card-count
badge and its title turned on its side, and the strip is deliberately not part
of the window's division: the expanded lanes' units divide what is left once
each folded strip's fixed width has come off the top, so folding a lane is a
re-divide trigger of the Show/Hide Trash family — the window never moves and
the siblings grow into what the lane gave up.
The state is a first-class lane frontmatter key, `collapsed: true`, and
document state exactly as `width` is: the files are the board, so an agent
folds a lane by writing one key. Absent means expanded, expanding removes the
key rather than writing `false` (the remove-at-default family beside a
one-unit `width`, the empty rename's `title` and the None well's
`background`), and the lane's `width` rides along untouched so expanding
restores the lane the user had. The read is `width`'s leniency one type over —
a boolean scalar or a quoted boolean word reads as itself, everything else has
no reading at all and renders as expanded, bytes preserved either way.
Toggling is the header's always-visible collapse chevron, the lane context
menu's single Collapse Lane / Expand Lane row, and a plain click anywhere on
the strip; a modified click on the strip stays the ordinary selection grammar,
so a folded lane is still selectable by pointer. The title reads bottom-up and
is justified to the top of the room below the strip's chrome (owner ruling
2026-08-08), truncating against the strip's own height.
While folded the lane draws no cards at all, which is what makes every
exclusion true by construction rather than by a guard per gesture: no card
face means no marquee target and no navigation frame, and no registered grid
means the masonry's drop zones have nothing to resolve against. What did need
code is the half that names absolute destinations — the option-arrow jumps and
the arrow seed scan past a folded lane, the lane domain's down-arrow is inert
on one, and New Card skips it (a selection inside one falls through to the
last-active lane, the stale selection's rule). A drop on the strip appends at
the lane's end, cards and Finder files alike, with an accent edge standing in
for the shadow the strip has no masonry to open; there is no hover-to-auto-
expand yet. Lane reorder works on the strip, and a dragged folded lane carries
its fold, so its shadow and its replica are the strip rather than its units.
The write is `writeLaneWidths` clause for clause — one `updateIndex` bracket,
the same stamp behaviour, the same three do-nothing paths — with two new
`WriteOperation` cases and two new undo verbs rather than one of each, because
a banner or an Edit-menu row that said "resize" after Collapse Lane would name
a control the user never touched.
Claude-Session: https://claude.ai/code/session_014PtZdPwqZuqEDLc6wZMtEy
Replaces the pathfinder-inherited round-robin deal (child i -> column i % C)
with contiguous column segments: base = n/C, the first n%C columns take one
more, and logical order runs down each column before crossing to the next.
Only the geometric mapping changes -- ranks, selection flatten, and VoiceOver
order are untouched, and MasonryPlacement stays the single placement function
both the Layout and the drop model replay.
Why: an insertion under round-robin shifted every later card across columns;
under the column-major deal later cards slide within their column and at most
one card crosses each boundary, so the drag reflow is far calmer. Drop-slot
math gets simpler too -- a column's cards are one contiguous range, a
non-final column's tail is now a genuine mid-list position, and only the last
column's tail means append.
DropSlotMathTests recomputed and extended (46 -> 50): the uneven-fill deal,
boundary positions, the shared tail/head boundary index, and a placement/
drop-model shadow-agreement check. DRAG-REORDER.md and DESIGN/10 amendments
are listed for ratification, deliberately not edited here.
Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY
04's settled clauses were mostly shipped already — the create landing
resolved through DropSlotMath.cardSlot with one nominal shadow per
importable file — but a release on the lane header fell through to the
card zones, which clamp inward, so a scrolled lane could propose behind
the header stripe. FileDropZones now folds header, attach hit-test, and
card-slot resolution into one pure seam asked in that order, the header
answering topmost per the ruling; lane headers register their frames
for it. FinderDrop.shadowCount names the floor-at-one rule. New tests
pin the header boundary, a differential against cardSlot's own zones
(same zones, not similar), and a store-level differential proving a
file landing takes the very ranks a card move there takes.
Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY
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
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
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