Improve FAQ accordion accessibility (ARIA and keyboard)

[Cbiux]

Summary

The FAQ accordion (components/landing/faq.tsx) works visually but lacks full keyboard and screen-reader semantics for an accessible disclosure pattern.

What to build

• Add aria-expanded, aria-controls, and unique ids on FAQ toggle buttons
• Link answer panels with role="region" and aria-labelledby
• Ensure category filter buttons have clear aria-pressed state
• Verify focus order and visible focus rings (ZK monochrome style)
• Optional: arrow keys to move between open items

Acceptance criteria

• FAQ passes basic axe/Lighthouse accessibility checks for the accordion
• Keyboard-only users can open/close all items
• No visual regression in ZK theme

Files

• components/landing/faq.tsx

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How to contribute

1. Comment before starting
2. Fork → branch (feat/faq-a11y)
3. Test with keyboard and VoiceOver/NVDA if possible
4. PR with Closes #15

Part of the GrantFox OSS program.

[xx7412421-cloud]

Hi, I'd like to work on this issue. Could you assign it to me? I'll keep the change focused on the FAQ accordion ARIA state, keyboard access, focus styling, and no visual regression.

[leocagli]

I'd like to work on this issue, please assign me so I can begin implementation.