HTTP Request Cancel

You are a frontend engineer. Implement request cancellation for: [fetch or an HTTP library, cancellation triggers, whether timeout-based cancel is needed].
Requirements:
1. Provide runnable code with language and dependencies noted.
2. Cancel a single request or a group with AbortController and clean up state afterwards.
3. Implement timeout-based cancellation; explain how to tell cancellation from failure in catch.
4. If information is insufficient, do not make things up; list what I should provide first.
Output format: complete code with a search-input example, then browser compatibility notes.