fix: repair cross-package bugs and test DOM/type configuration

[stooit]

Summary

Fixes all failing tests and type errors in the monorepo. bun test && bunx tsc --noEmit now passes cleanly from the repo root (13 pass, 0 fail; tsc exit 0).

Bug fixes (source root-causes)

1. Renamed hook / stale import — apps/web/src/lib/api.ts imported useThrottle, but the hook in packages/utils was renamed to useDebounce. Updated the import and re-exported it as useSearchDebounce (the name the test expects).
2. Button accessibility — icon-only Button now sets an aria-label so it has an accessible name.
3. DataTable stale closure — sort-direction toggle used a value captured in a stale closure, so "sort descending on second click" failed. Switched to a functional state updater to read the latest direction.
4. Date formatting locale — packages/utils/src/format/date.ts used a locale/format that swapped day and month. Now uses a locale-correct dateStyle: 'short' so day 1 is not confused with month 1.

Test/type infrastructure

• Root bunfig.toml — added the happy-dom setup preload so React component tests get a DOM when bun test runs from the repo root (previously only wired into packages/ui/bunfig.toml, which is not read at root level → document is not defined).
• tsconfig.json — added bun-types so bun:test imports resolve under tsc --noEmit.

Verification

• bun test → 13 pass / 0 fail
• bunx tsc --noEmit → exit 0
• No test files modified; no new dependencies added.

Notes / assumptions

• All existing packages (happy-dom, @happy-dom/global-registrator, bun-types) were already installed — nothing new added.
• Reviewed by the review subagent: APPROVE — all four fixes address genuine root causes with no masking or regressions.