Select: `description` slot throws "Invalid slot" inside a Dialog

[kcacosta]

Describe the bug

<Text slot="description"> inside a Select throws when the Select is inside a Dialog:

Error: Invalid slot "description". Valid slot names are "subtitle".

Dialog provides a TextContext whose only slot is subtitle (Dialog.tsx). react-aria's Select does provide its own TextContext with a description slot, but it isn't in scope where the Select's children are first evaluated — RAC renders them once to build the collection, outside that provider — so the Text resolves against the Dialog's context and throws.

TextField in the same position works, which is what makes this look like a Select bug rather than intended Dialog behavior.

To Reproduce

Three cases, run against @launchpad-ui/components 1.19-era RAC in jsdom:

Composition	Result
Select + Text slot="description", outside a Dialog	works
TextField + Text slot="description", inside a Dialog	works
Select + Text slot="description", inside a Dialog	throws

render(
  <Dialog aria-label="Example">
    <Select>
      <Label>Organization role</Label>
      <Button>
        <SelectValue />
      </Button>
      <Text slot="description">Provides access to organization settings.</Text>
      <Popover>
        <ListBox items={items}>{(item) => <ListBoxItem id={item.key}>{item.name}</ListBoxItem>}</ListBox>
      </Popover>
    </Select>
  </Dialog>,
);
// Error: Invalid slot "description". Valid slot names are "subtitle".

Moving the Text outside the Select but still inside the Dialog throws the same way.

Expected behavior

A Select in a Dialog should support its description slot, the way TextField already does, so a select-shaped form field in a modal or drawer can carry helper text that is announced as the control's description.

Impact / workaround

Any select field with helper text inside a modal or drawer. The workaround is a plain element wired up by hand:

<Select aria-describedby={helperId}>…</Select>
<span id={helperId} className={styles.helper}>Provides access to organization settings.</span>

That means restating the description typography in local CSS and losing the slot's aria-describedby wiring. It's now duplicated across two fields in gonfalon's invite-members drawer (OrganizationRoleField, ProjectAccessField) and will spread to every select-with-helper-text field in a dialog until this is fixed.

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🤖 Filed by Claude Code on behalf of @kcacosta, from work on gonfalon's invite-members drawer.