[feature] Add useInterval Hook to @termuijs/jsx

[karthikj5453]

Which package?

@termuijs/jsx

What happened?

@termuijs/jsx attempts to re-export useInterval in packages/jsx/src/index.ts from ./hooks.js. However, packages/jsx/src/hooks.ts does not contain an implementation or export for useInterval.

Importing useInterval directly from @termuijs/jsx fails at runtime/module-import with a missing export error.

Steps to reproduce

import { useInterval } from '@termuijs/jsx';

function TimerComponent() {
    useInterval(() => {
        console.log('tick');
    }, 1000);
    return null;
}


## GSSoC contributor?

- [x] Yes. You contribute under GSSoC 2026 and want to work on this.

[github-actions]

✅ Auto-assigned to @karthikj5453 (issue opener).

Open your PR by 2026-08-10 (7 days). The bot frees this issue for another contributor after that date.

Reminders:

• ⭐ Star the repo first. The star-check job blocks your merge otherwise.
• PR title: type: short description
• Link this issue in your PR body: Closes #3440

Good luck. 🚀