Docs gallery: the six components-form-calendar entries author the bare "calendar" keyword, which belongs to plugin-calendar's ObjectCalendar

[yinlianghui]

Measured while implementing #4616 (the gallery registration widening). Filed unassigned; not fixed there — the ruling on that card scopes it to registration and has entry-shape defects censused and filed rather than rewritten. Duplicate-searched (keyword + ui:calendar / skipFallback / the category path): no open issue covers it.

The defect

All six entries under examples/schema-catalog/src/schemas/components-form-calendar/ author the date-picker primitive as the bare keyword:

{ "type": "calendar", "mode": "single", "className": "rounded-md border" }

But packages/components/src/renderers/form/calendar.tsx deliberately registers that primitive under ui:calendar only — skipFallback: true, with the reason in the file:

// `calendar` collides with the plugin-calendar full CRUD calendar VIEW,
// which owns the bare `type: 'calendar'` schema keyword; this date-picker
// primitive is reached via `ui:calendar` only.

So the bare keyword resolves to @object-ui/plugin-calendar's ObjectCalendar, which is a data-bound event calendar. The entries carry no data source, so it throws its own guard (packages/plugin-calendar/src/ObjectCalendar.tsx:282).

Measured, rendering all 423 entries the way the gallery does

• Before Docs gallery: 35 catalog entries render the red "Unknown component type" panel because their plugin package is never loaded on that page #4616 (plugin-calendar not loaded on that page): 6 tiles paint Unknown component type: calendar (OBJUI-001).
• After Docs gallery: 35 catalog entries render the red "Unknown component type" panel because their plugin package is never loaded on that page #4616 (plugin-calendar loaded): the same 6 tiles paint Error: DataSource required for object/api providers.

One red tile for another — the registration widening cannot help this category, which is why these six are named as an explicit exclusion, with this issue number, in examples/schema-catalog/test/catalog-gallery-render.test.tsx.

Affected: custom-style, date-range, form-integration, multiple-dates, simple-calendar, single-date. (form-integration is a div whose child is the offending node, so its root type resolves and only the nested one does not.)

Fix shape (not prescriptive — there is a real question here)

Mechanically the fix is "type": "ui:calendar" in six files. The question worth answering first is whether this category should demo the primitive at all: the catalog is the corpus AI authoring tools retrieve from, and an entry teaching the namespaced spelling of a keyword whose bare form means something else is a different teaching decision from dropping the category. Related: whether the bare/namespaced split is discoverable enough at authoring time, given that the only signal today is a comment in the renderer.

Refs #4616, PR #4615.