docs(skills): the html-tier page example spells object-metric's aggregate in the object form (#21667)

Fixes #21627
Clause-②: no

## Summary

`skills/objectstack-ui/rules/pages.md:160`, the `object-metric` line of
the `kind: 'html'` example, read `aggregate="count"`. The metric tile
reads `aggregate` as an object: at the objectui pin `ab187972`
(`.objectui-sha` at `eea82af67`),
`packages/plugin-dashboard/src/ObjectMetricWidget.tsx` `computeOne`
(`:452`–`:497`) sends `{ field: aggregate.field, function:
aggregate.function, groupBy, filter }` to `ds.aggregate` and reads the
answer back under `aggregate.function === 'count'` through `r.count`
(its own comment: "the literal `'count'` for a fieldless count"), so a
count needs `function: 'count'` and no `field`. The string form hands
both members over as `undefined`: the build passes with a warning and
the tile draws no number.

The line now reads `aggregate={{"function":"count"}}`, the html tier's
own expression spelling the example's sibling attributes already use
(`style={{"maxWidth":…}}`, `gap={6}`). One attribute value changed; no
other byte of the file, no other file. The sibling surfaces already
spell the object form (`rules/dashboards.md:125`, the
`analytics-inline-vs-dataset` eval) and are untouched.

## Positive control: the html tier's own compile, before and after

`@objectstack/sdui-parser` `compile(source, manifest)` over the
example's `source` template literal, with the committed repo-root
`sdui.manifest.json` (the manifest `os build` resolves through
`packages/cli/src/utils/sdui-manifest.ts`; it declares `object-metric`'s
`aggregate` input as `type: "object"`):

- before (`eea82af67`): `ok=true`, 1 diagnostic: `[warning]
type-mismatch: object-metric prop "aggregate" expected an object` (the
tag is spelled bare here; the diagnostic prints it in angle brackets);
the compiled node carries `aggregate: "count"`.
- after (`d5e95044e`): `ok=true`, 0 diagnostics; the compiled node
carries `aggregate: {"function":"count"}`.

The script and its raw output are in the dev report comment on #21627.

## Readings

| reading | before (`eea82af67`) | after (`d5e95044e`) |
|---|---|---|
| `skills/objectstack-ui/rules/pages.md`, whole file, lines | 453 | 453
|
| whole package, sum of every `skills/**/SKILL.md` (10 files), lines |
4397 | 4397 |
| `scripts/check-skills-token-ratchet.mjs`, `pages.md` | 5676 / 5692
(headroom 16) | 5679 / 5692 (headroom 13) |

Bytes 22701 → 22716 (+15). Net lines 0. No ceiling moved. Token count
reported because the sibling gate (`check-skills-token-ratchet`) defines
one; there is no second token gate on this file.

## Gates run locally at `d5e95044e`

Derived with `node scripts/pm/dispatch-gates.mjs --commands` (no paths;
change set from the merge base `eea82af67`): 23 commands. Every one run,
exit captured before any pipe; `--ran` reconciliation attached in the
report.

- `node scripts/check-ci-filter-parity.mjs`: exit 0, "OK: all 193
declared cross-package glob(s) … are covered".
- `node scripts/check-closing-keyword-parity.mjs`: exit 0;
`--self-test`: exit 0, "40 assertions, 5 mutations … each driven to
red".
- `node scripts/check-comment-mask-corpus.mjs`: exit 0, "8127 files, 0
disagree, 0 unparseable".
- `node scripts/check-doc-route-spelling.mjs --advisory`: exit 0,
"population clean"; `--self-test`: exit 0.
- `node scripts/check-skills-token-ratchet.mjs`: exit 0, "54 authored
bundle file(s) within their ceilings"; `--self-test`: exit 0, "65 cases
pass".
- `pnpm --filter @objectstack/lint run check:doc-formula-expressions`
(after building the `@objectstack/lint` closure under the verify lock,
VERDICT command-exit 0): exit 0.
- `pnpm check:agent-test-spelling` · `check:corpus-claim-drift` ·
`check:cross-package-test-inputs` · `check:doc-authoring` ("53 published
skill files clean") · `check:driver-memory-census` ·
`check:gitlink-declared` · `check:nul-bytes` ("scanned 10035 text
file(s) … no raw ASCII control bytes") · `check:pm-governed-merges` ·
`check:refd-timer-probe` · `check:role-word` ·
`check:skill-compatibility` ("10 SKILL.md file(s) reconciled") ·
`check:skill-frame-sync` · `check:skill-identifier-liveness` ("457
citation(s) over 53 published file(s)") · `check:watch-hint-literal`:
all exit 0.

Dispatch-named leads outside the derived list:

- `pnpm --filter @objectstack/spec run check:skill-docs`: exit 0, "Skill
docs in sync".
- `pnpm --filter @objectstack/spec run check:skill-examples`: first run
exit 3, `PREREQUISITE NOT MET` (no `client-react` dist; nothing
measured); after building the `@objectstack/client-react` closure under
the verify lock (VERDICT command-exit 0, 210s held), exit 0: "260 prose
examples type-check across 3 surface(s)". The edited html example block
carries no `os:check` marker (the file's two markers sit at `:64` and
`:211`), so this gate reads no byte of the diff; it is run because the
dispatch named it.

NOT MEASURED locally, CI's own: the `Test Core` shards, the four
type-check lanes, the 11 whole-tree families, the 55 artifact-roster
families and the 15 changeset-derived families (this PR carries no
changeset: `skills/**` is shipped by `npx skills add` from the
repository, and no published package's `files[]` lists it; measured, see
the report).

## 维护者速读(草稿)

### 改了什么
对外发布的 UI 技能包 `skills/objectstack-ui` 里,`rules/pages.md` 的 `kind: 'html'`
页面示例中 `object-metric` 那一行的 `aggregate` 属性,由字符串 `"count"` 改为对象
`{{"function":"count"}}`。全文件只动这一个属性值:行数 453 → 453,整包 SKILL.md 行数 4397 →
4397,token 棘轮 5676 → 5679(上限 5692 未动)。

### 为什么改
这一行是技能包教给 AI 作者的「标准示例」。原来的字符串写法 `os build` 只给一条
warning(构建照样通过),而指标卡组件读的是对象(`aggregate.field` /
`aggregate.function`),字符串下两个成员都是 undefined,页面上这块指标卡不显示数字 ——
技能本身在教一种「构建通过、运行时静默空白」的写法。同一技能包里 `dashboards.md` 与 eval
用的都是对象形,只有这一行走偏。实测:改前 html 层编译 1 条 `type-mismatch` 警告,改后 0 条。

### 风险与代价(含回滚)
纯文本改动,不碰代码、schema 或任何其它文件;发布面是 `skills/**`(经 `npx skills add` 进客户项目),不走
npm,无 changeset。回滚即 `git revert` 本 PR 的单个 commit。已知残余:html 层对字符串形仍只给
warning 而非 error,卡与分诊裁决都把它划在本卡范围外,本 PR 不碰。

### 席位意见
(留空,席位定稿)

### 你要做的
本 PR 触及 `skills/**`(Tier H),需要你的一次 APPROVED review;之后由席位落地。你不需要手改任何东西。

## Acceptance notes

- The card cites the objectui pin `89cad75d557`; `.objectui-sha` at
`eea82af67` is `ab187972`. The `computeOne` reading above is taken at
`ab187972` (`:452`–`:497`) and holds there. Noted, not filed.
- The html tier's `type-mismatch` severity (a string handed to an
`object`-typed input is a warning, not an error) is out of scope by the
card's own words and the triage ruling; noted, not filed.
- `rules/dashboards.md:125` spells the react tier's object form as a JSX
object literal (single quotes); this html-tier line spells JSON, as its
sibling attributes do. Both are the object form; neither changes.
- The `kind: 'html'` example block is not an `os:check`-marked block
(markers at `pages.md:64` and `:211` only), so `check:skill-examples`
cannot see this line; the positive control above is the measurement that
stands in for it.
- No changeset: `skills/**` is outside every published package's
`files[]` (measured over every tracked `package.json`); `skip-changeset`
requested through `scripts/pm/label-write.mjs`.

---
_Generated by [Claude
Code](https://claude.ai/code/session_01CB6W87z22K2yjUCDyVrJRk)_

Co-authored-by: Claude <noreply@anthropic.com>

Author: objectstack-fleet[bot]

skills/objectstack-ui/rules/pages.md

@@ -157,7 +157,7 @@ export const ReleaseNotesPage = definePage({
   source: `
 <flex direction="col" gap={6} style={{"maxWidth":"768px","margin":"0 auto","padding":"40px"}}>
   <h1 style={{"fontSize":"32px","fontWeight":700,"color":"hsl(var(--foreground))"}}>Release Notes</h1>
-  <object-metric objectName="ticket" aggregate="count" label="Open tickets" />
+  <object-metric objectName="ticket" aggregate={{"function":"count"}} label="Open tickets" />
 </flex>`,
 });
 ```