#136 chore: update to latest Qwik v2

Summary by cubic

Upgrade Qwik to v2.0.0-beta.37 and migrate to the new Signal API. Fix the double-render in pkg.pr.new preview by removing the extra router config.

• Dependencies

  • Update @qwik.dev/core, @qwik.dev/router, and eslint-plugin-qwik to 2.0.0-beta.37 across the repo.
  • Bump tooling: vite to 7.3.5 and vue-tsc to ~3.1.0.
  • Remove pnpm.patchedDependencies for @qwik.dev/router.

• Migration

  • Replace ReadonlySignal<T> with Readonly<Signal<T>> across hooks, types, components, and docs.
  • Update preview to export default createQwikRouter({ render }); remove qwikRouterConfig.