v0.1.0

Restructure as installable npm package js-tls-fetcher

Move package.json from node/ to the repo root and rename the package to
js-tls-fetcher, matching the repo. npm cannot install from a git subdirectory,
so a root manifest is what makes this work:

    npm install github:Elalitareq/js-tls-fetcher

The helper binary still resolves to node/bin/, relative to node/index.js. The
files array ships the Go source (cmd/, fetcher/, go.mod, go.sum) so postinstall
can build from source on a machine that has Go, and falls back to downloading
the platform binary from Releases when it does not.

postinstall now reads the manifest from the repo root rather than node/, which
is what repoSlug() needs to derive the Releases URL.

Also add node/index.d.ts so TypeScript consumers get typed request/response
shapes and the named-profile union.

CI:
- run the end-to-end test via `npm install` + `npm test` from the root, which
  exercises the same postinstall path a consumer hits
- test on macOS as well as Linux
- cross-compile every release target, so a v-tag cannot fail halfway and
  publish a Release with missing platform assets
- pack-check asserts the tarball still carries the Go source; without it,
  postinstall on a Go-less machine has nothing to build from

Release:
- verify-version fails on a tag/package.json version mismatch, before anything
  is published
- publish-npm runs with `needs: build`, so Release assets are always uploaded
  before the package whose postinstall downloads them
- publish is skipped with a warning when no NPM_TOKEN secret is set, keeping
  the GitHub install path independent of registry auth

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>