fix: repair cross-package bugs and clear type errors

[stooit]

Summary

Fixes all 5 failing tests and eliminates all tsc --noEmit type errors across the monorepo. Bugs spanned three packages plus a type-resolution config issue.

Area	Fix
apps/web/src/lib/api.ts	The hook was renamed in packages/utils (useThrottle → useDebounce); the app still imported the old name. Import the current name and re-export it as useSearchDebounce (the export the test expects).
packages/ui/src/components/Button/Button.tsx	Icon-only buttons lacked an accessible name. Apply aria-label so the button is reachable by accessible name.
packages/utils/src/format/date.ts	formatDate produced ambiguous/locale-wrong output (01/03/2024). Now emits the documented DD/MM/YYYY (en-AU) contract, fixing the day-1 vs month-1 confusion.
tsconfig.json + bun-env.d.ts	bun:test types are now resolved via a scoped /// <reference types="bun-types" /> file instead of clobbering the global types array (which had suppressed other ambient @types). Test glob added to include.

Verification

• bun run test → 13 pass / 0 fail
• bunx tsc --noEmit → 0 errors

Notes / assumptions

• No test files modified; no dependencies added — changes are minimal and target only what the tests require.
• The "stale closure re-render" area (DataTable) was investigated; its tests already passed, so it was left unchanged per the "fix only what tests require" constraint.
• date.ts builds the formatted string from local date parts (getDate/getMonth/getFullYear) because Bun's ICU pads the day under Intl.DateTimeFormat; this matches every test assertion with no timezone/off-by-one risk for the test inputs.

🤖 Generated autonomously.