docs(skills): put the GanttConfig keys back under the gantt block

[os-litant]

Fixes #6508

skills/objectui/guides/page-builder.md headed one table "Top-level display /
behavior options (siblings of gantt on props, not field mappings)" and then
listed two different populations under it. This splits them, moving rows rather
than adding prose.

Read-site verification (measured, not recalled)

packages/plugin-gantt/src/ObjectGantt.tsx, line numbers on
546f61099 + this branch:

Key	Read site	Face
resourceView	ganttConfig?.resourceView (1635)	GanttConfig
assigneeField	ganttConfig?.assigneeField (1021, 1055)	GanttConfig
effortField	ganttConfig?.effortField (1058, 1065)	GanttConfig
capacity	ganttConfig?.capacity ?? 1 (1640)	GanttConfig
quickFilters	ganttConfig?.quickFilters (1108), destructured (727)	GanttConfig
autoZoomToFilter	ganttConfig?.autoZoomToFilter (1297, 1305)	GanttConfig
viewMode	ganttConfig?.viewMode (1641, 1651)	GanttConfig
criticalPath	schema.criticalPath (1669)	node
showBaselines	schema.showBaselines (1672)	node
skipWeekends	schema.skipWeekends (1071)	node
holidays	schema.holidays (1072)	node
markers	schema.markers (1666)	node
persistLayout	schema.persistLayout (1203)	node
readOnly	schema.readOnly (1673, 1743)	node
mobileReadOnly	schema.mobileReadOnly (1674)	node

Every read site the card named is confirmed, with one spelling nit: capacity is
ganttConfig?.capacity ?? 1, not ganttConfig.capacity. Same face either way.

getGanttConfig (line 508) checks schema.gantt first and returns the block
whole; the flat top-level face is branch 2 and is reached only when there is no
block and both date fields are present. So beside a gantt block, every key in
the GanttConfig group is read by nothing.

The split is not an inference from the read sites alone — the declaration draws
the same line by construction. In packages/types/src/zod/objectql.zod.ts,
ObjectGanttSchema takes the GanttConfig group from SpecGanttConfigSchema.shape
by reference (lines 676, 726-731) and declares the node group locally
(689-707).

Seven keys move, not six

viewMode was not enumerated on the card but has the identical shape:
SpecGanttConfigSchema.shape.viewMode by reference at line 676, read only as
ganttConfig?.viewMode, and therefore also in FLAT_GANTT_CONFIG_KEYS — so
objectui#6469's dev-mode warning names it when it is hoisted beside a block.
Leaving it in the top-level table would have re-shipped the same false teaching
for one key while fixing it for six. Flagged here rather than filed separately
because it is the same defect in the same table this PR is already rewriting.

Conversely markers, persistLayout and mobileReadOnly were not enumerated
either and measure as genuinely node-level, so they stay where they sat — the
node-level population is eight rows, not five.

Before / after table structure

Before — one table, 13 rows, heading true for 6 of them:

**Top-level display / behavior options** (siblings of `gantt` on `props`, not field mappings)
  criticalPath  showBaselines  skipWeekends  holidays          -- node-level, correct
  resourceView  assigneeField/effortField/capacity             -- GanttConfig, inert beside a block
  quickFilters  autoZoomToFilter                               -- GanttConfig, inert beside a block
  markers  viewMode  persistLayout  readOnly  mobileReadOnly   -- viewMode: GanttConfig; rest node-level

After — two tables, 13 rows total, unchanged row bodies:

**Gantt config options** (`GanttConfig` members - set them INSIDE `gantt`, or hoist
the whole config as above; beside a `gantt` block a top-level copy is IGNORED)
  resourceView
  assigneeField / effortField / capacity
  quickFilters
  autoZoomToFilter
  viewMode

**Node-level display / behavior options** (true siblings of `gantt` on the node
itself, not `GanttConfig` members - they apply with either face)
  criticalPath  showBaselines  skipWeekends  holidays
  markers  persistLayout  readOnly  mobileReadOnly

Three further corrections inside that move

1. The backwards row is dropped, not reworded. The assigneeField /
   effortField / capacity row ended "Also usable as field mappings under
   gantt." Under gantt is where they work; the row now sits in the gantt-config
   table, so the clause is deleted rather than inverted.
2. The worked example is a working shape again. It carried a gantt block
   plus top-level quickFilters and autoZoomToFilter — the exact dead shape the
   card names. Those two keys move inside the block (a pure move, no line
   change). Every remaining top-level key in the example (criticalPath,
   skipWeekends, holidays, readOnly) is genuinely node-level, so
   FLAT_GANTT_CONFIG_KEYS now intersects the example's top level in zero keys
   and objectui#6469's warning fires zero times on it.
3. The node-level heading no longer says "on props". That phrase
   contradicted this guide's own rule two sections earlier — "Every key belongs on
   the node itself — never in a props envelope" — and the schema.X read sites.
   Since the heading was being rewritten anyway, the claim is not re-authored
   into the replacement sentence.

Kept verbatim: "The gantt field config may also be hoisted to top-level
props instead of nesting under gantt." That sentence is true — "instead of"
does real work, and it describes branch 2 exactly.

Line counts (published-skills ruling, 2026-08-21)

Measure	Before	After	Delta
skills/objectui/guides/page-builder.md (whole file)	510	516	+6
Whole published package (all 18 .md under skills/)	5673	5679	+6
skills/objectui/SKILL.md	155	155	0
Rows in the affected tables	13	13	0

Measured with git show origin/main:PATH | wc -l against git show HEAD:PATH, not
estimated from the diff.

The +6 is the second table's scaffolding and nothing else: one blank separator,
two heading lines, one blank, one header row, one separator row. No teaching
paragraph is added; one clause is deleted. git diff --shortstat: 1 file
changed, 20 insertions, 14 deletions.

Gates

Derived from package.json plus the workflows that carry no path filter, not
recalled. Exit codes captured by redirecting first, so no tail masks them.

Gate	Command	Verdict line it printed	Exit
skills-paths	node scripts/check-skills-paths.mjs	"check-skills-paths: OK (93/94 stated path(s) resolve across 18 guide file(s); 1 baselined)."	0
doc-fences (self-test)	node scripts/check-doc-fence-languages.mjs --self-test	"check-doc-fence-languages self-test: 26 cases pass"	0
doc-fences	node scripts/check-doc-fence-languages.mjs	"check:doc-fences - every TypeScript block in 223 document(s) is fenced ts/tsx/typescript..."	0
control-bytes	node scripts/check-control-bytes.mjs	"check-control-bytes: OK (scanned 5593 tracked text file(s); skipped 85 binary)."	0
changeset-presence	node scripts/check-changeset-presence.mjs	"No source of a released package changed in this range, so no changeset is owed."	0
doc-links	node scripts/check-doc-links.mjs	"Links are valid across 17 scan roots."	0

Scope notes, so the greens are readable:

• skills-paths is the gate that measures this file. Confirmed by
  --list, which prints a token from skills/objectui/guides/page-builder.md:29
  — the file is in its scan set, not merely adjacent to it. This diff adds no new
  path token, so the green is a no-regression reading.
• doc-links green is NOT a reading of this file. skills is absent from its
  SCAN_ROOTS (scripts/check-doc-links.mjs, line 583 onward). Recorded as run,
  not as coverage.
• doc-component-types and doc-snippet-types are not owed.
  check-doc-component-types.mjs line 212 states it walks content/docs "and
  nothing else: not skills/**"; check-doc-snippet-types.mjs roots at
  content/docs plus package READMEs.
• No changeset, and no skip-changeset label. The gate's own verdict is
  quoted above. In this repo the skip-changeset label exempts nothing — no
  workflow or script reads it — so it is deliberately not applied.
• Narrowed local scope, declared: no pnpm install, no build, no unit run.
  This diff touches one .md file and no source; each gate above imports only
  node: builtins, verified by reading their import blocks. eslint does not lint
  markdown here.

Also checked by hand: grep -naP for control bytes over the edited file (no
match), and all 10 json fences in the guide re-parsed with json.loads (10
parse, 0 fail).

Drift protection

No code companion is owed. objectui#6469's dev-mode warning plus
ObjectGantt.blockPrecedence.test.tsx ("names GanttConfig keys hoisted beside a
block, with no top-level date pair") already pin the runtime behaviour this guide
now describes.

Draft on purpose: skills/** is a published surface and goes the maintainer
review path.

Generated by Claude Code

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Generated by Claude Code