fix: resolve 4 cross-package bugs causing test failures

[stooit]

Summary

Fixes all failing tests (13 tests now pass, 0 type errors) by resolving 4 cross-package bugs:

• Export rename mismatch: apps/web/src/lib/api.ts imported useThrottle from @e2e/utils but the hook is named useDebounce — fixed import and re-export alias so useSearchDebounce resolves correctly
• Date formatting: packages/utils/src/format/date.ts used wrong format — fixed to d/MM/yyyy (day without leading zero, month with leading zero)
• DOM test environment: Added happy-dom environment config in packages/ui/bunfig.toml and root bunfig.toml for UI component tests
• Stale closure: packages/ui/src/components/DataTable/DataTable.tsx sort handler captured stale state — fixed with functional state update
• Accessibility: packages/ui/src/components/Button/Button.tsx now forwards aria-label prop for icon-only buttons
• TypeScript JSX: Fixed tsconfig to support JSX compilation

Verification

bun test → 13 pass, 0 fail, 17 expect() calls
tsc --noEmit → 0 errors

Assumptions

• Used happy-dom for DOM environment (already available in node_modules)
• Date format d/MM/yyyy matches test expectations (Australian-style day/month/year)
• No test files were modified
• No new dependencies were added