fix: repair failing tests and type errors across monorepo

[stooit]

Summary

Fixes all failing tests and type errors in the multi-package monorepo. After these changes bun test && tsc --noEmit passes cleanly from the repo root (13 pass / 0 fail, tsc exit 0). No test files were modified and no dependencies were added.

Bugs fixed

#	File	Bug	Fix
1	apps/web/src/lib/api.ts	Imported/re-exported useThrottle, renamed to useDebounce in @e2e/utils (TS error + runtime crash)	Import and re-export useDebounce; useSearchDebounce alias preserved
2	packages/utils/src/format/date.ts	formatDate emitted a zero-padded day (01/03/2024); test expects unpadded (/^1/)	Use dateStyle: 'short' with en-AU → 1/3/24
3	packages/ui/src/components/Button/Button.tsx	aria-label destructured but never applied — icon-only buttons had no accessible name (WCAG 2.2 SC 4.1.2)	Apply aria-label; dev-only warning + fallback label when omitted
4	packages/ui/src/components/DataTable/DataTable.tsx	Stale-closure bug: second sort click didn't toggle direction	Functional updater setSortDir(prev => ...)
5	bunfig.toml	UI tests failed with document is not defined under a root bun test run	Preload the happy-dom setup.ts at the root bunfig
6	tsconfig.json	Cannot find module 'bun:test' — bun-types not auto-included	Add "types": ["bun-types"]

Notes / assumptions

• DOM root cause differed from first hypothesis: Bun has no environment config option (Vitest concept) — the root bunfig's environment = "happy-dom" was inert. DOM comes solely from GlobalRegistrator in packages/ui/test/setup.ts, and Bun uses the bunfig nearest the cwd, so a root run never loaded the package-scoped preload. Fix: add the preload to the root bunfig. setup.ts (a test file) was not edited.
• Date format: the defect was zero-padding, not field ordering — en-AU already orders day-first, but numeric fields always zero-pad. Only dateStyle: 'short' yields an unpadded day. This produces a 2-digit year (24); the test asserts nothing about the year.
• Button a11y: test 3 requires an icon-only button with no aria-label to still expose a non-null accessible name, hence the fallback + dev warning.

Verification

$ bun test        → 13 pass, 0 fail
$ bunx tsc --noEmit → exit 0

No files under any test/ directory were modified.