test(types): pin the PartialSchema collapse, plus the #5155 sequencing note

.changeset/6397-partial-schema-collapse-pin.md

@@ -0,0 +1,43 @@
+---
+'@object-ui/types': patch
+---
+
+`PartialSchema<T>` is pinned as collapsed, and its doc comment now says so
+(objectui#6397). Nothing about the type changes — the declaration is deliberately
+left exactly as written.
+
+The alias promises "all properties optional except the type" and does not deliver
+it. Every instantiation declares exactly ONE property, `type`, and carries a live
+`[key: string]: any`, so it accepts any key at `any`. Measured through the
+TypeScript checker against the emitted `index.d.ts` — the same instrument that
+produced objectui#6269's 61 -> 0 reading:
+
+ PartialSchema<ObjectGridSchema> -> 1 declared property: type (source: 61)
+ PartialSchema<ObjectFormSchema> -> 1 declared property: type (source: 67)
+ PartialSchema<ObjectViewSchema> -> 1 declared property: type (source: 42)
+ PartialSchema<ButtonSchema> -> 1 declared property: type (source: 27)
+
+`Omit<T, K>` is `Pick<T, Exclude<keyof T, K>>`, and `keyof T` on a type carrying a
+string index signature is `string | number` — the literal member names are
+absorbed. Every `T extends BaseSchema` inherits `BaseSchema`'s `[key: string]: any`
+(objectui#5155), so `Partial<Omit<T, 'type'>>` rebuilds a type holding the index
+signature and none of the named members. This is objectui#6151's collapse
+(heritage clause) and objectui#6269's (property position) in a third position: a
+generic mapped-type alias, which is why neither of their guards sees it — #6151's
+walks the `LayoutSchema` union, #6269's reads `ObjectViewSchema`'s two slots.
+
+**Why a pin and not a repair or a retirement.** Triage ruled on 2026-08-25 that
+retiring the alias is a removal of a published export of `@object-ui/types` — a
+breaking removal of published capability, which sits on the human floor — and that
+escalating it today would spend the maintainer's attention on a question
+objectui#5155 is expected to moot. Repair in place is unavailable: `T` is generic,
+so there is no literal key list to `Pick` the way #6269 could for its two concrete
+schemas, and every generic re-spelling collapses for the same `keyof T` reason.
+Once #5155 removes the root index signature, the alias starts working as written
+with no edit at all. What this ships is the removal of the one impermissible
+state — *declared, published, collapsed, and unpinned*.
+
+No runtime code, no type declaration and no accepted value changes; a consumer's
+`PartialSchema<X>` means exactly what it meant before. Declared `patch` rather
+than as a no-release so the doc-comment warning actually reaches the published
+`.d.ts` a consumer reads — that warning is the deliverable half of the card.