fix: repair cross-package bugs causing test and type failures

[stooit]

Summary

Fixes all failing tests and type errors across the monorepo. The failures spanned three packages and a shared tsconfig. All 13 tests pass and bunx tsc --noEmit is clean.

Changes

• packages/utils — A hook was renamed useThrottle → useDebounce but consumers still imported the old name. Added a re-export alias useDebounce as useSearchDebounce from the package barrel so @e2e/utils exposes the name the test expects, without duplicating the implementation.
• apps/web/src/lib/api.ts — Updated to import/re-export useSearchDebounce (was importing the removed useThrottle), fixing both the runtime test and the tsc error.
• packages/utils/src/format/date.ts — formatDate produced zero-padded / wrong-order output. Switched to a locale-correct day-first short format so dates like 1 March render 1/03/... rather than month-first or zero-padded.
• packages/ui/Button — Icon-only buttons weren't forwarding aria-label to the DOM. Now forwards an explicitly supplied aria-label, and applies a sensible default for icon-only buttons when none is given (accessibility requirement from the test).
• tsconfig.json + bun-env.d.ts — Test files use bun:test, which tsc couldn't resolve. Fixed via an ambient /// <reference types="bun-types" /> file rather than a types array, to avoid disabling automatic @types/* discovery (which could break a real Next.js build).

Verification

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

Assumptions

• DataTable's controlled re-render test already passed; left untouched (no stale-closure bug present).
• No test files modified; no dependencies added — fixes are limited to what the tests require.
• Icon-only default aria-label chosen to satisfy the "non-null accessible name" assertion when no label is passed.