[react] Add commandFor and command attributes to ButtonHTMLAttributes

Summary

The Invoker Commands API adds commandfor and command attributes to <button>. These are missing from ButtonHTMLAttributes in @types/react.

HTML spec

• whatwg/html PR: https://github.com/whatwg/html/pull/9841
• MDN: https://developer.mozilla.org/en-US/docs/Web/API/HTMLButtonElement/commandForElement

Browser support

• Chrome/Edge 135+
• Safari Technology Preview
• Firefox Nightly (behind flag)

Expected types

interface ButtonHTMLAttributes<T> extends HTMLAttributes<T> {
  commandFor?: string | undefined
  command?: string | undefined
}

command accepts built-in values (toggle-popover, show-popover, hide-popover, show-modal, close, request-close) and custom strings (prefixed with --).

Current workaround

Projects augment the module locally:

import 'react'

declare module 'react' {
  interface ButtonHTMLAttributes<T> extends HTMLAttributes<T> {
    commandFor?: string
    command?: string
  }
}

React already ships popoverTarget and popoverTargetAction on button — commandFor/command is the successor API from the same spec space.

Start at ButtonHTMLAttributes in @types/react and compare its existing popover-related attributes with the HTML spec and MDN links. Add the two optional string attributes shown in Expected types, then verify that TypeScript consumers no longer need the module augmentation workaround.