fix(components): forward refs from the UI kit form components

.changepacks/changepack_log_ui_kit_forward_ref.json

@@ -0,0 +1,7 @@
+{
+  "changes": {
+    "packages/components/package.json": "Patch"
+  },
+  "note": "Button, Checkbox, Input, Radio and Textarea forward their ref to the button, input or textarea they render, so a ref reaches the form element on React 18 as well as React 19",
+  "date": "2026-10-01T00:00:00.000Z"
+}

packages/components/src/__tests__/forward-ref.browser.test.tsx

@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'bun:test'
+import { render } from 'bun-test-env-dom'
+import { createRef } from 'react'
+
+import { Button, Input, Radio, Textarea } from '../index'
+
+describe('forwardRef', () => {
+  it('hands each component ref to its form element', () => {
+    const button = createRef<HTMLButtonElement>()
+    const input = createRef<HTMLInputElement>()
+    const radio = createRef<HTMLInputElement>()
+    const textarea = createRef<HTMLTextAreaElement>()
+    render(
+      <>
+        <Button ref={button}>b</Button>
+        <Input ref={input} />
+        <Radio ref={radio}>r</Radio>
+        <Textarea ref={textarea} />
+      </>,
+    )
+    expect(button.current?.tagName).toBe('BUTTON')
+    expect(input.current?.tagName).toBe('INPUT')
+    expect(radio.current?.type).toBe('radio')
+    expect(textarea.current?.tagName).toBe('TEXTAREA')
+  })
+})

packages/components/src/__tests__/index.browser.test.ts

@@ -4,12 +4,12 @@ describe('export', () => {
   it('should export components', async () => {
     const index = await import('../index')
     expect({ ...index }).toEqual({
-      Button: expect.any(Function),
-      Input: expect.any(Function),
-      Textarea: expect.any(Function),
+      Button: expect.any(Object),
+      Input: expect.any(Object),
+      Textarea: expect.any(Object),
       Stepper: expect.any(Function),
       Select: expect.any(Function),
-      Radio: expect.any(Function),
+      Radio: expect.any(Object),
       RadioGroup: expect.any(Function),
       SelectContainer: expect.any(Function),
       SelectDivider: expect.any(Function),
@@ -23,7 +23,7 @@ describe('export', () => {
       SelectContext: expect.any(Object),
       useSelect: expect.any(Function),
       Toggle: expect.any(Function),
-      Checkbox: expect.any(Function),
+      Checkbox: expect.any(Object),
     })
   })
 })