spaces: a timeline and a workload chart, as view layouts

[nyblnet]

Two new shapes on the view layout control, branched off origin/main and
depending on none of the unmerged feature branches.

• gantt — one bar per page, from its start date to its due date. Today
  marked; overdue work outlined; bar colour from the grouping field's option.
• workload — the first vt:"number" field in the schema, summed per
  bucket, drawn by kernel/src/charts.ts (read-only import, the path dash
  already uses). The bucket is groupBy, defaulting to the person field.

Both read the view's existing source, filter, sort and groupBy, so
{"layout":"workload","source":{"under":"<page>"},"filter":{"open":true}} is
"the workload for this project, open only" with no new key anywhere.

The chart host: a layout, not a chart block

Argued in spaces/src/gantt.ts and recorded in docs/DECISIONS.md, because
every chart this app grows inherits it.

1. Both shapes need source/filter/sort/groupBy and nothing else. A
   chart block would grow four keys with those same four meanings — two
   vocabularies for one question, permanently, in every file ever saved.
2. The degradation is better and it was measured. A shell built from
   origin/main, shown {"type":"view","layout":"gantt"}, renders a board
   of the same pages, keeps layout:"gantt" through a save, and keeps the new
   start prop blocks — checked in a browser against a real build. A chart
   block falls to the unknown-type path and renders its html: one line of text
   where a schedule was.
3. The honest counter-argument is in the source and recorded rather than
   dismissed: a workload chart really is an aggregate. It loses on scope — the
   aggregation is a property of the output while every input key keeps the
   meaning it had. A chart of data that is not pages (a table block's
   numbers) should be its own block type, and this is not a precedent against
   that.

start, and why absent start is not an edge case

The tracker shipped with due and nothing else. Every issue in every file
already written therefore has a due date and no start — so those draw as a
milestone diamond at the due date, not a zero-width bar. Symmetric: a start
with no due is a diamond too. Neither date at all: left out, and counted.

Wrong data, decided rather than left to arithmetic

case	what it does
due before start	drawn between the two dates that are really in the file, flagged — never silently swapped
malformed date (2026-13-99, prose, an object)	an absent date
negative / NaN / Infinity estimate	excluded from the sum and counted — a −3 absorbed into a bar makes somebody look lighter than the work they hold
10,000-page view	capped at 300 bars / 20 buckets, deterministically ordered, and it says what it left out; the workload tail is folded, so the visible bars still sum to the document
prototype-shaped bucket names (__proto__, toString)	a Map tally, no prototype chain to fall through

Every date comparison is an integer day number computed arithmetically
(days-from-civil); no Date is constructed for any comparison.

Print and the static preview

Colour and geometry travel as presentation attributes inside the SVG, not in
styles.css — which the file-manager still's own stylesheet is not. Measured:
disabling the app stylesheet leaves the picture identical in colour and in every
proportion (uniform 1.228× rescale from the container width alone), and both
charts arrive in the serialized [data-bento-preview] host with their fills,
fitting a 300px thumbnail box with no overflow.

Not built, and what is left room for

Dependencies and critical path. Both need a typed page reference, which
exists only on the unverified spaces-relations branch. No field invented, no
second way to express a page reference. What is left for them at zero format
cost: GanttModel.bars is a flat list keyed by pageId, each carrying its
resolved x/w on a shared 0..1 axis — an arrow is two lookups and two
numbers, a critical path is a walk over the same list. The edges will live on
the pages, not on the view block, so neither needs this module or the format to
change shape.

Verification

• node scripts/test-spaces.mjs — all 9 rigs pass, including the new
  scripts/test-spaces-gantt.ts (114 behavioural checks, registered in the
  runner and in ci.yml under a five-timezone matrix). Whole suite also green
  under TZ=Pacific/Kiritimati and TZ=Pacific/Niue.
• tsc --noEmit clean; npm run build:single + shell-gate.mjs pass.
• 11 sabotages, each restored from an in-memory copy: 11/11 red under
  TZ=Pacific/Kiritimati, 10/11 under TZ=UTC. The one that differs is the
  point — replacing the arithmetic day number with new Date(y, m-1, d) is
  invisible from inside UTC and off by a day in UTC+14.
• Browser-verified on a uniquely-named copy over http://127.0.0.1, with a
  build-marker check on every probe: bar geometry read with
  getBoundingClientRect, SVG <a href="#p/…"> routing confirmed by an actual
  navigation, the full six-step layout cycle returning the block to a deleted
  layout key, and the workload Group button reading Group · Assignee rather
  than Group · Status.
• Byte cost, origin/main and this branch built back to back: +13,304 B
  (277,769 → 291,073), of which +6,180 B is the shared chart engine, probed
  on its own. test-spaces-size.mjs reports +32,619 B against a drifted
  reference; that number is not the change.

Format additivity

layout:"gantt"/"workload" are stored words; board remains the absent
key, so a view cycled all the way round is byte-identical to one nobody touched
(verified in the browser). start is an ordinary optional prop block carrying
its own readable html. Nothing is repurposed and no docId is regenerated.

Notes for the reviewer

• Touches two ops-surface files under the shared-surface rule, claimed by path:
  scripts/test-spaces.mjs (one RIGS entry) and .github/workflows/ci.yml (one
  step). Registration is not optional — the manifest check fails without both.
• scripts/test-spaces-model.ts has two assertions that hardcoded
  nextLayout('gallery') === 'board'; the cycle is six long now and they were
  updated in place.
• render.ts still has the duplicated, unreachable table branch tracked on the
  board as spaces-table-unreachable. Left alone — not this change's to fix.
• Six is the ceiling for a cycling layout button; a seventh shape should convert
  that control to a picker. Written down in fields.ts at the site.

[github-actions]

Build size

main (0100083) → spaces-gantt (5008cce)

app	base	PR	change
bento/slides	677.9 KiB	677.9 KiB	0.0 KiB (0.00%)
bento/spaces	271.3 KiB	284.3 KiB	+13.0 KiB (+4.79%)
bento/dash	424.1 KiB	424.1 KiB	0.0 KiB (0.00%)

Updated: 2026-09-10T22:15:59Z