react-dom/client guarantees hydrateRoot in React 18+, so the guarded
createRoot().render() fallback was dead code. Render each server-serialized
instance with hydrateRoot directly; renderToString stays the server path, so
behavior is otherwise unchanged.

Serialize a server-rendered Hypernova payload (via renderToString +
serialize), render it into a jsdom document, then call renderReact's client
branch and assert the component resumes on the server node with the
server-provided props under React 19.

Uses jest-environment-jsdom since the hypernova() client path runs only when
a DOM is present.

- Replace the commented-out single server signature with real overloads for
  both the server and client branches of renderReact, plus the exported
  ServerRenderedComponent (props -> HTML string) mapping.
- Add tsconfig.json (strict, React JSX, NodeNext module resolution) so the
  package's own declarations are verified by tsc --noEmit on TypeScript 7 via
  the npm run typecheck script.

- Bump checkout and setup-node to v4 in both CI and publish workflows.
- Test across the current active Node LTS lines (20.x, 22.x, 24.x) instead
  of the old 16.x-20.x matrix, and publish on Node 24.
- CI now runs an explicit build plus tsc typecheck before the jest suite so
  compile output, type checking, and tests are all verified.

Update the README tagline to reflect the widened peer dependency range.