Add focus-return tests for Modal and Drawer primitives

[Abidoyesimze]

Summary

Keyboard users should return to the triggering control after closing overlays.

Affected files

• src/components/ui/Modal.tsx
• src/components/ui/Drawer.tsx
• src/hooks/useFocusTrap.ts

Tasks

• Verify focus trap and restore behavior in Modal and Drawer.
• Add tests covering open → close focus return.
• Fix any regressions in useFocusTrap.

Acceptance criteria

• Scope is limited to the files listed (or agreed alternatives in the PR).
• Change is verifiable: tests, screenshots, or written QA steps in the PR.
• No behavior regressions in related user flows.
• No new duplicate abstractions without a one-line rationale in the PR.

Suggested labels

cleanup, a11y, testing

Notes

Standalone cleanup issue from CLEANUP_ISSUES_2026-05.md. Complements the audit queue and product backlog.