ci: add npm publish workflow and scoped package metadata

[fqueis]

Description

This branch prepares @fqueis/openapi-contract for public npm distribution. It adds a GitHub Actions publish workflow (OIDC trusted publishing), updates package.json for the scoped package name and publish metadata, and refreshes the README so consumers can install and run the server via npx from npm.

Key Changes & Features Implemented

CI / Publishing

• Add a Publish workflow on main (and workflow_dispatch) that skips when the version is already on npm, then runs lint/test/build, creates a GitHub Release, and publishes with npm trusted publishing (OIDC). (4c1ac84)

Package metadata

• Rename the package to @fqueis/openapi-contract, set author/homepage/repository/bugs, add public publishConfig, and run pnpm run build via prepublishOnly. (da842ea)

Documentation

• Add an npm version badge, recommend Cursor MCP usage via npx -y @fqueis/openapi-contract, clarify that pnpm is for contributors, and keep local built-JS setup under local development. (0b5268b)

How to Test

1. Confirm package.json name is @fqueis/openapi-contract, version is 1.0.0, and publishConfig.access is public.
2. Review .github/workflows/publish.yml for id-token: write, Node 22.14, the already-published gate, and the lint → test → build → release → publish path.
3. Run pnpm lint, pnpm test, and pnpm build locally to match the workflow gates.
4. Verify README Cursor MCP snippet uses npx with @fqueis/openapi-contract, and that local contributor steps still document pnpm build/test.
5. After merge (and npm Trusted Publisher bootstrap), push a version bump on main or use workflow_dispatch and confirm the workflow publishes or correctly skips an already-published version.