docs(react-carousel): Add autoplayInterval control to Autoplay story

[Copilot]

Update Carousel Autoplay Example to Include autoplayInterval Prop

Resolves the issue where the Autoplay example didn't clearly demonstrate how to use the autoplayInterval prop.

• Analyze the current Carousel Autoplay example implementation
• Add a control to demonstrate the autoplayInterval prop
• Update the example to pass the autoplayInterval to the Carousel component
• Verify the changes work correctly with manual testing
• Update story documentation
• Run tests and linting (all passed)
• Address code review feedback
• Run security checks (no issues found)
• Add change file as requested

Changes Made

1. Added Input control for autoplayInterval prop in the Autoplay example

   • Allows users to set custom autoplay interval in milliseconds
   • Includes a helpful hint showing "Delay between slides: {value}ms"
   • Defaults to 4000ms (matching the default prop value)
   • Input validation ensures values >= 1000ms (aligned with min attribute)

2. Connected the interval control to the Carousel component by passing the autoplayInterval prop

3. Updated story documentation to explain the autoplayInterval prop and its default value

4. Added beachball change file for tracking this documentation update

Screenshot

The updated example now clearly demonstrates:

• How to use the autoplayInterval prop
• Real-time feedback showing the current interval value
• Interactive control to test different interval values

Testing & Validation

✅ Build: Passed - yarn nx run react-carousel:build
✅ Linting: Passed - yarn nx run react-carousel:lint
✅ Tests: All 203 tests passed - yarn nx run react-carousel:test
✅ Manual verification: Autoplay advances slides at the specified interval (tested with 2000ms)
✅ Code review: Feedback addressed (validation aligned with min attribute)
✅ Security: No issues found - CodeQL analysis
✅ Change file: Created for @fluentui/react-carousel

Security Summary

No security vulnerabilities were introduced or found in this change. This is a documentation-only change to a Storybook example.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Update the Carousel Autoplay example to include autoplayInterval prop</issue_title>
<issue_description>### Component

Carousel

Package version

latest

React version

19

Environment

System:
    OS: macOS 26.3
    CPU: (16) arm64 Apple M3 Max
    Memory: 16.01 GB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Browsers:
    Chrome: 145.0.7632.76
    Edge: 145.0.3800.58
    Safari: 26.3
  npmPackages:
    @fluentui/react-icons: ^2.0.306 => 2.0.311 
    @fluentui/react-icons-northstar: 0.66.5 => 0.66.5 
    @fluentui/react-northstar: 0.66.5 => 0.66.5 
    @types/react: 19.2.2 => 19.2.2 
    @types/react-dom: 19.2.2 => 19.2.2 
    react: 19.2.0 => 19.2.0 
    react-dom: 19.2.0 => 19.2.0

Current Behavior

The autoplay example doesn’t clearly demonstrate how to use the autoplayInterval prop, and because it’s not linked to the autoplay button, it causes confusion for users.

Expected Behavior

The autoplay example clearly demonstrates how to set the interval at which the carousel slides are displayed.

Reproduction

https://stackblitz.com/edit/bpbcbk5d?file=src%2Fexample.tsx

Steps to reproduce

N/A

Are you reporting an Accessibility issue?

None

Suggested severity

Low - Has or doesn't need a workaround

Products/sites affected

No response

Are you willing to submit a PR to fix?

yes

Validations

• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Update the Carousel Autoplay example to include autoplayInterval prop #35755

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[dmytrokirpa]

@copilot add change file by running yarn change

[Copilot]

@copilot add change file by running yarn change

Change file created for @fluentui/react-carousel with type "none" (documentation update). See commit a362d72.