Install pinned packages into pluginDir/node_modules.
No-op if pluginDir/node_modules already exists (idempotent).
The dir is content-addressed by the caller.
Parameters
pluginVersions: Record<string,string>
pluginDir: string
showOutput: boolean = false
When true, npm output flows to the terminal (useful at high verbosity).
When false (default), npm output is suppressed; stderr is captured and
included in any thrown error.
Install pinned packages into
pluginDir/node_modules. No-op ifpluginDir/node_modulesalready exists (idempotent). The dir is content-addressed by the caller.