fix: resolve all cross-package test failures and type errors

[stooit]

Summary

• Renamed hook export: Added useSearchDebounce as a named re-export from @e2e/utils (the hook was renamed from useThrottle/useDebounce but consumers still imported the old name)
• Fixed stale import: Updated apps/web/src/lib/api.ts to import useSearchDebounce instead of the non-existent useThrottle
• Accessibility fix: Ensured the Button component passes through aria-label for icon-only buttons
• Stale closure fix: Changed DataTable sort handler to use functional state update, preventing stale closure on re-renders
• Date format fix: Corrected formatDate to output day without leading zero (Australian locale: d/MM/yyyy)
• DOM test environment: Added happy-dom preload to packages/ui/bunfig.toml so UI component tests have access to document
• Type declarations: Added bun-types to tsconfig.json so bun:test module resolves without type errors

Verification

All 13 tests pass (bun run test) and tsc --noEmit exits clean.

Assumptions

• The test expectation for useSearchDebounce is the canonical name; the source was behind
• Australian date locale (d/MM/yyyy) is the intended format based on test expectations
• bun-types was already installed in node_modules — no new dependency added