Fix #26: Modal focus trap for Settings / Add role / JD triage

[partbomb]

This PR adds a keyboard focus trap for modals (Settings, Add role, JD triage) when using the Tab key, improving accessibility. Fixes #26.

[cursor]

Thank you for picking up #26 — the Tab / Shift+Tab cycle while a .modal is open is exactly the right shape, and CI looks good.

A couple of pieces from the issue still missing before we can merge as “fixes #26”:

1. Initial focus on Settings — Add role / JD triage already focus a field; Settings open still leaves focus behind the dialog. Please move focus into #settings when it opens (first input or close control is fine).
2. Restore focus to the opener on close — when Settings / Add role / JD triage close, return focus to the button that opened them.
3. Accessible name — give each of those modals aria-labelledby (pointing at the existing heading) or aria-label, matching the drawer’s dialog pattern.

Happy to merge once those land. Appreciate you taking the a11y work.

[telivity-otaip]

Thank you for picking up #26 — the Tab / Shift+Tab cycle while a .modal is open is exactly the right shape, and CI looks good.

A couple of pieces from the issue still missing before we can merge as “fixes #26”:

1. Initial focus on Settings — Add role / JD triage already focus a field; Settings open still leaves focus behind the dialog. Please move focus into #settings when it opens (first input or close control is fine).
2. Restore focus to the opener on close — when Settings / Add role / JD triage close, return focus to the button that opened them.
3. Accessible name — give each of those modals aria-labelledby (pointing at the existing heading) or aria-label, matching the drawer’s dialog pattern.

Happy to merge once those land. Appreciate you taking the a11y work.