Migrate to Trusted Publisher

[pgerke]

As a DevOps engineer
I want to migrate our npm package publishing process to use npm Trusted Publisher authentication
So that we eliminate long‑lived tokens and improve the overall security of our CI/CD pipeline.

Acceptance Criteria

• Configure npm Trusted Publisher for the npm packages.
• Update GitHub Actions workflows to include id-token: write permissions.
• Ensure the CI environment uses npm >= 11.5.1 to support OIDC authentication.
• Validate that pnpm publish works seamlessly via the underlying npm publish command.
• Remove legacy npm auth tokens and secrets from repository settings.
• Document the new publishing flow in the project’s README or CONTRIBUTING guide.