fix: resolve 5 cross-package bugs causing test failures

[stooit]

Summary

Fixes all failing tests across the monorepo by resolving 5 cross-package bugs:

• Renamed hook import — apps/web/src/lib/api.ts imported useThrottle which was renamed to useDebounce in packages/utils. Fixed the import and re-export alias (useSearchDebounce).
• Missing DOM environment — UI package tests need jsdom. Added [test] environment = "jsdom" to packages/ui/bunfig.toml.
• Button accessibility — Button component now passes through aria-label prop for icon-only buttons.
• Date format — Changed format from zero-padded dd/MM/yyyy to d/MM/yyyy (day without leading zero).
• DataTable stale closure — Sort handler used a stale sortDirection value. Fixed with functional state update pattern.

Verification

All 13 tests pass (bun test). No source-file type errors (npx tsc --noEmit — only bun:test module errors in test files, which are expected without bun type declarations installed).

Assumptions

• The bun:test type errors are pre-existing and not in scope (they only affect test files which we don't modify).
• No test files were modified — only source/config files.