finding(app-shell): four studio-design consumers on an empty metadata registry — one renders NOTHING on a field click, one states a false reason

[claude]

Split out of #6795 by the domain:ui execution seat (PM session session_01CRJge11jso9TpXRWFt1Z49) after that card's measurement round. #6795 keeps only its registry-observability question (a published-contract change, now needs-user-decision); this card is the half that stands on its own and touches no contract.

⛔ This card is NOT a lazy conversion and must not become one. It changes what four studio-design consumers say when a metadata registry read returns undefined. No registry, no bundling, no sideEffects, no eager-closure ceiling.

What was measured

#6795's implementer drove all four consumers against genuinely empty registries — the probes assert emptiness first (listMetadataPreviewTypes() and listMetadataInspectorTypes() both [], all three getMetadataDefaultInspector reads undefined) rather than assuming it. Observed renders:

consumer	state on an empty registry	verdict
ObjectSettingsPanel	prints "No default object inspector registered."	✅ already honest — leave it
ObjectHooksPanel	falls back to a working generic SchemaForm	✅ already honest — leave it
ObjectActionsPanel	renders only the action's own label — no editor, no explanation	⚠️ silent
StudioDesignSurface interfaces canvas	prints "design support is in progress"	⛔ factually wrong
StudioDesignSurface.tsx:3076	selecting a FIELD with getMetadataInspector('object') undefined ⇒ aside count 0	⛔ clicking a field does nothing at all

⭐ Note the first two rows: #6795's card body claimed all four were silently empty, and two of them were not. Anyone repairing this should re-drive the probes rather than trusting any table, this one included.

The three repairs

1. StudioDesignSurface.tsx:3076 — the real defect. A field click renders nothing: no inspector, no message, no indication anything was clicked. ⭐ This is a genuine latent bug and it is only unreachable today by accident — registration happens eagerly at module scope, so the undefined branch is never taken in production. It is one lazy conversion, one registration-order change, or one plugin-load failure away from being live.
2. ObjectActionsPanel — say why there is no editor, rather than rendering a bare label that reads as a finished surface.
3. The interfaces canvas message — "design support is in progress" is not true; the support exists and the registry is empty. A wrong explanation is worse than none, because it sends the reader to the wrong place.

Acceptance

• ⛔ A test per repaired consumer that drives an empty registry and asserts a VISIBLE state. A "does not crash" assertion does not discharge this — silence is precisely the failure. Reuse finding(app-shell): ~141 KB of the console eager closure is previews/inspectors pinned by four SYNCHRONOUS studio-design registry reads — a different contract from the ComponentRegistry (arm C of #6776) #6795's probe shape: assert the registries are genuinely empty first, then assert what renders.
• ⚠️ The two already-honest consumers want pins too, so a future refactor cannot quietly regress them into the silent class. That is the cheap half and it is where this card's durability lives.
• ⛔ Do not repair by making the registries observable, or by changing when registration happens. Both belong to finding(app-shell): ~141 KB of the console eager closure is previews/inspectors pinned by four SYNCHRONOUS studio-design registry reads — a different contract from the ComponentRegistry (arm C of #6776) #6795 and one of them is a published-contract change on a manual floor.

Contention note

Lands entirely in packages/app-shell/src/views/studio-design/. ⚠️ packages/app-shell currently sits under seven unmerged PRs, so keep the diff tight; the file-level overlap with those PRs is nil today but the package is hot.

Provenance

#6795 (parent, needs-user-decision on registry observability) · #6795's measurement comment carries the full probe output, the reproduced subtree byte figures, and the recovery probe showing a consumer that reads an empty registry never recovers when registration lands later — which is why "just make it lazy" was refused.

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Generated by Claude Code