Use corepack install (no args) to read the npm version from package.json's packageManager field

corepack install without arguments reads the packageManager field from the current directory's package.json and installs that exact version into the corepack cache, activating it for subsequent commands. This keeps CI and local development pinned to a single source of truth and avoids drift that occurs when a workflow hard-codes corepack prepare npm@X --activate separately from the packageManager field. Combine with corepack enable npm so bare npm routes through the shim at the pinned version.

In CI that checks out a package.json, prefer corepack enable npm && corepack install over hard-coded corepack prepare npm@X.Y.Z --activate; the version then travels with the tag/commit being built.