Harden Workboard modal and drawer accessibility.
Summary:
- Add Workboard dialog focus lifecycle handling for initial focus, Tab/Shift+Tab containment, Escape close, and opener restore.
- Mark Workboard background content inert/aria-hidden while modal or drawer dialogs are active.
- Add focused unit and Chromium browser smoke coverage for the audited modal/drawer accessibility requirements.
- Keep UI browser test aliases able to resolve shared workspace packages used by the Workboard view.
Verification:
- node scripts/run-vitest.mjs ui/src/ui/views/workboard.test.ts
- node scripts/run-vitest.mjs ui/src/ui/views/workboard.browser.test.ts
- (cd ui && pnpm exec vitest run --config vitest.config.ts --project browser src/ui/views/workboard.browser.test.ts)
- GitHub checks green at 6557012430
