fix: resolve failing tests and type errors across monorepo

[stooit]

fix: resolve failing tests and type errors across ui, utils and web packages

Changes

• apps/web api.ts: import renamed useDebounce (stale useThrottle)
• ui Button: apply aria-label (WCAG 2.2 SC 4.1.2) with fallback + dev warning
• ui DataTable: functional state update fixes stale closure in sort toggle
• utils formatDate: en-AU unpadded day via formatToParts
• bunfig.toml: preload happy-dom setup (Bun ignores environment)
• tsconfig.json: types: [bun-types] (existing devDependency)

Verification

bun test: 13 pass / 0 fail; tsc --noEmit: 0 errors. No test files modified, no deps added.

Assumptions / notes

• Button test requires non-null aria-label even without caller input, hence generic fallback.
• Root package.json --preload flag now redundant but harmless; left as is.
• Pre-existing: DataTable sortable not keyboard-operable (WCAG 2.1.1) — follow-up recommended.