fix: repair cross-package test failures and type errors

[stooit]

Summary

Fixes all failing tests and eliminates all type errors across the monorepo. bun test now reports 13 pass / 0 fail and npx tsc --noEmit is clean. The bugs spanned all three packages and their interdependencies.

Fixes

1. apps/web/src/lib/api.ts — renamed-hook import. useThrottle was renamed to useDebounce in @e2e/utils, but the old name was still imported/re-exported. Updated both while preserving the useSearchDebounce alias a test depends on.

2. packages/ui/.../Button.tsx — missing accessibility attribute. The aria-label prop was destructured but never forwarded to the <button>, so icon-only buttons had no accessible name. Now forwarded (WCAG 4.1.2).

3. packages/ui/.../DataTable.tsx — stale-closure bug. handleSort read sortDir from the render scope, going stale across re-renders. Switched to the functional setSortDir(prev => ...) updater — caught by the controlled re-render test.

4. packages/utils/src/format/date.ts — date formatting. Replaced fragile explicit Intl.DateTimeFormat options with a locale-aware format for en-AU, giving portable day-first output.

5. Test environment wiring — bunfig.toml (root + packages/ui). happy-dom environment/preload wasn't fully configured, so React Testing Library renders failed with document is not defined. Added the complementary environment = "happy-dom" and preload entries.

6. tsconfig.json — bun:test types. Added "types": ["bun-types"] (already installed) so bun:test/Bun globals resolve under tsc. strict unchanged — no relaxation of type checking.

Constraints honoured

• No test specs modified (only source + setup/config files).
• No new dependencies added (bun-types, happy-dom were already present).
• Each change is minimal and traceable to a specific failing test.

Verification

• bun test → 13 pass / 0 fail
• npx tsc --noEmit → clean
• Independent code review: approved, no blocking concerns.