fix: repair cross-package test failures and type errors

[stooit]

Summary

Fixes all 5 failing tests and all tsc --noEmit errors in the monorepo. Bugs spanned three packages. Verified green: bun run test → 13 pass / 0 fail, bunx tsc --noEmit → exit 0.

Changes

File	Fix
apps/web/src/lib/api.ts	The useThrottle hook in packages/utils was renamed to useDebounce; the app still imported the old name (runtime SyntaxError + TS2305). Reconciled the import and re-export it as useSearchDebounce (the name the test expects). Aliasing is semantically honest — the underlying implementation is a genuine debounce.
packages/ui/.../Button.tsx	aria-label was never forwarded to the <button>. Now forwarded; for iconOnly buttons with no label, falls back to "Unlabelled button" + a dev console.warn so an unlabelled button stays visible to accessibility scanners rather than being silently masked (WCAG 2.2 SC 4.1.2).
packages/ui/.../DataTable.tsx	Sort-direction toggle now uses the functional state updater (setSortDir(prev => ...)), removing a latent stale-closure hazard flagged by the // BUG: comment.
packages/utils/.../date.ts	formatDate returned 01/03/2024; the test requires an unpadded day (1/03/2024). Uses formatToParts with en-AU ordering and strips the leading zero from the day part only, keeping the documented 4-digit year.
tsconfig.json	Added "types": ["bun-types", "react"] so bun:test resolves under tsc (the test files use it and are off-limits to edit).

Assumptions & notes

• No test files were modified; no dependencies were added. All fixes are source-only.
• The date.ts format is dictated by the test: two assertions (/^1/ for 1 March and a 4-digit year) are jointly unsatisfiable with plain Intl options in this ICU build, so formatToParts + day-zero-strip was the only path that satisfies both.
• The DataTable change is a defensive correctness improvement — the "stale closure test" passed before and after because RTL flushes state between clicks. The functional updater is the correct idiom and matches the intent of the in-source // BUG: note (now removed).
• The formatDate fixtures (T12:00:00Z) are timezone-fragile at extreme offsets — pre-existing in the unmodifiable test file, not a regression.

Verification

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