Some environments like Vercel require building in their own environment
where only Node.js is available. There is no Deno, no Bun, and no way
to download pre-built staticalize binaries. Publishing to npm as
`staticalize` means `npx staticalize` works in these Node-only CI
environments.

- Add dnt build producing ESM npm package with bin entry point
- Add build:npm and build:jsr tasks
- Restructure publish workflow with verify-jsr/verify-npm pattern
- Publish to both JSR and npm with provenance
- Migrate CLI to configliere, imports to import map, tests to @std/expect