fix: repair failing tests across ui, utils, and web packages

[stooit]

Summary

Fixes all failing tests and type errors across the monorepo. Baseline was 8 pass / 5 fail with 1 blocking type error; now 13 pass / 0 fail and tsc --noEmit is clean. No test files modified, no dependencies added.

Root causes & fixes

1. apps/web/src/lib/api.ts (type error TS2305) — the hook useThrottle was renamed to useDebounce in packages/utils, but api.ts still imported the old name. Updated the import and kept the public useSearchDebounce re-export intact (satisfies api.test.ts).

2. packages/ui Button — icon-only buttons never applied aria-label to the rendered <button>, leaving them without an accessible name (WCAG 2.2 SC 4.1.2). Now aria-label is passed through, with a fallback label for icon-only buttons and a dev-only console.warn prompting callers to supply a meaningful label.

3. packages/ui DataTable — the sort toggle read state captured at handler-creation time. Switched to the functional setState updater form so the toggle always reads current state.

4. packages/utils date.ts — formatDate produced a zero-padded day (01/03/2024); the en-AU day-first test expects an unpadded day (1/03/2024). Fixed the format so the day is not zero-padded.

5. tsconfig.json — added "types": ["bun-types"] (already a devDependency) to resolve pre-existing Cannot find module 'bun:test' errors so tsc --noEmit is fully clean. No new dependency added.

Verification

• bun run test -> 13 pass / 0 fail
• bunx tsc --noEmit -> clean (exit 0)

Assumptions

• Ran the project test script (which preloads the happy-dom setup) as the source of truth; a bare root bun test skips the preload and produces spurious document is not defined errors.
• Kept the fixes minimal and test-driven per the task constraints (no test edits, no new deps). A follow-up review noted optional UX/convention refinements for the Button fallback label and AU date format, but those would require changing test assertions and are intentionally left out of scope.