fix: resolve 4 cross-package bugs causing test failures

[stooit]

Summary

Fixes all 9 failing tests across 4 test files in this TypeScript monorepo by addressing 4 cross-package bugs:

• Renamed hook (apps/web/src/lib/api.ts): The useDebounce hook in packages/utils was imported as useThrottle and re-exported as a non-existent name. Fixed to import useDebounce and re-export it as useSearchDebounce (which the web app's test expects).

• Date format (packages/utils/src/format/date.ts): Changed format string from dd/MM/yyyy to d/MM/yyyy — the test expects no zero-padding on the day.

• Stale closure (packages/ui/src/components/DataTable/DataTable.tsx): The sort click handler captured stale state. Fixed by using functional setState update (prev => ...) so it always reads the latest sort direction.

• Accessibility (packages/ui/src/components/Button/Button.tsx): The Button component wasn't passing through aria-label. Fixed by spreading remaining props onto the button element.

• DOM environment (bunfig.toml): UI tests failed with document is not defined because bun 1.3.14 doesn't support environment = "happy-dom" in bunfig.toml. Fixed by preloading a setup script that calls GlobalRegistrator.register().

Verification

bun test → 13 pass, 0 fail
npx tsc --noEmit → only expected 'bun:test' module errors remain

Assumptions

• The bun:test TypeScript errors are pre-existing and acceptable (bun runtime types not in tsconfig)
• happy-dom global registration is safe for all test files (non-DOM tests are unaffected)