Synthesized `aside` region carries `className`, which `PageRegionSchema` rejects — a Reference Rail page has no persistable spelling

[yinlianghui]

Observation

buildDefaultPageSchema emits the Reference Rail's region as

{ name: 'aside', width: 'small', className: 'hidden xl:flex flex-col gap-4', components: [ … ] }

PageRegionSchema (@objectstack/spec, packages/spec/src/ui/page.zod.ts) declares
name / width / components only, and it is closed under the same ADR-0089 D3a
.strict() flip as the page component shape. Parsing that region against the vendored
spec (17.0.0-rc.6) gives:

unrecognized_keys | <root> | Unrecognized key(s) on this page region: `className`.
 Until #4001 closed this shape these were dropped silently — the page still rendered,
 without whatever the key was meant to configure.

So a synthesized page that carries the Reference Rail has no spelling a server write
would accept.

Why this is filed as an observation, not a defect

It is not reachable from any persisted payload today. The only path that stores a
synthesized page is Studio's page-create seed
(packages/app-shell/src/views/metadata-admin/anchors.ts → createSeed), which calls
buildDefaultPageSchema(objectDef) with no options — so showReferenceRail is off,
slots.rightRail is empty, and the aside region is never emitted into the PUT. Every
other caller (RecordDetailView, PagePreview) renders the tree in the browser and
never writes it, where the region's className is honoured by RegionContent
(packages/components/src/renderers/layout/page.tsx) and everything works.

It is worth recording because it is the same defect class as #4232 (which fixed the
component-level half — props now go in the spec's properties carrier), and because the
day anything persists a page with the rail on, that write fails the same way page-create
did.

Why #4232 did not fix it

Unlike recordChrome / items, this key has no spec-shaped carrier. The options and
their costs, so whoever picks this up does not have to re-derive them:

• Drop the className — loses the responsive hide (hidden xl:) and the rail's own
  flex flex-col gap-4 spacing. The rail would render at every width, taking a column
  from the main content on laptop widths, which is the layout the class exists to prevent.
• Move it onto the child components — PageComponentSchema does declare className
  and responsiveStyles, but the hide has to apply to the region wrapper: hiding the
  children leaves an empty column occupying its width below xl. The gap-4 between
  siblings is a container concern and has no per-child spelling at all.
• Give PageRegionSchema a carrier (a className, or an ADR-0065 responsiveStyles
  at region level) — an objectstack-lane spec change, and the only option that keeps the
  semantics intact. Needs the usual "is there real business pull" read: today the only
  author of a region className is this synthesizer.

Evidence

Measured on objectui origin/main @ 49ae9f42d with the vendored @objectstack/spec
17.0.0-rc.6, by parsing buildDefaultPageSchema(def, { showReferenceRail: true, related: [ …2 lists ] })'s
aside region with PageRegionSchema.safeParse.

Related: #4232 (component-level half, fixed).

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Generated by Claude Code

[os-zhuang]

Findings triage (first grade): HOLD — stays finding.

Premise accepted as measured (card @ 49ae9f42d, re-read this round @ 6d8231c): PageRegionSchema is closed and declares name/width/components only, while buildDefaultPageSchema's Reference Rail region carries className. Dormant by the card's own reachability analysis — the only persisting caller (Studio page-create seed) calls the builder with no options, so the aside region never enters a PUT; render-only callers honour the class and never write.

Why held rather than escalated: the only semantics-preserving fix (a region-level className/responsiveStyles carrier on PageRegionSchema) is an objectstack spec-lane change whose sole author today is this synthesizer — zero business pull, which under the four-lens discipline defaults to defer. The card's option analysis is complete and on-card; the day anything persists a rail page, this graduates to a domain:spec card in objectstack (file-at-destination) with this thread as the evidence.

本评论来自分诊座位 Routine（#5474 试点），不构成认领。

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Generated by Claude Code

[os-steve]

Concentrated finding round (unified triage seat, 2026-08-17): graded pm:on-hold, type Task. Unreachable from any persisted payload today (the only storing path calls buildDefaultPageSchema with no options, so the aside region is never written), and the real fix is a spec-shaped carrier for region-level styling — a packages/spec contract question that should not be opened without a producer. Seat-graded hold (not a maintainer ruling).

Restart-when: any persistence path emits the aside region — re-check with grep -rn "showReferenceRail\|rightRail" packages apps for a caller that feeds a PUT/save, and re-verify PageRegionSchema's key set on the then-current spec. On discharge this becomes a spec-seat card (file at destination, objectstack domain:spec) for the region styling carrier, with this card as the objectui consumer half.

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Generated by Claude Code

[os-zhuang]

Triage: domain:ui (lane only — pm:on-hold untouched). Landing: packages/app-shell / packages/components — the synthesized aside region carrying a className that PageRegion refuses.

Routed via the maintainer direct-dispatch channel, this session, verbatim: 「然后 批 4–5」. PM session session_0124Qg8rLvpXnQDwCmpKUmaJ. objectui three-stream split (maintainer 2026-08-21); not a Routine triage fire — the triage seat may re-grade.

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Generated by Claude Code