fix(date-picker): update date schema to use z.coerce.date and enhance story assertions

- Changed date validation in form schema to use z.coerce.date for better handling of date inputs.
- Added assertion to check for the presence of submission confirmation text in the story.

Author: jaruesink

apps/docs/src/remix-hook-form/date-picker.stories.tsx

@@ -9,7 +9,7 @@ import { z } from 'zod';
 import { withReactRouterStubDecorator } from '../lib/storybook/react-router-stub';
 
 const formSchema = z.object({
-  date: z.date({
+  date: z.coerce.date({
     required_error: 'Please select a date',
   }),
 });
@@ -166,6 +166,8 @@ export const Default: Story = {
     // Check if this is the date picker button
     expect(updatedPickerButton.getAttribute('aria-haspopup')).toBe('dialog');
 
+    expect(canvas.getByText('Submitted with date:')).toBeInTheDocument();
+
     // Verify the button's text is no longer just "Select a date"
     const buttonText = updatedPickerButton.textContent || '';
     expect(buttonText).not.toContain('Select a date');