pnpm v12 resolved `pnpm add <pkg>` without a version, and a version-less
`npm:` or `jsr:` dependency, to the `latest` dist-tag even when the `tag`
setting named another one. pnpm v11 reads `tag` from pnpm-workspace.yaml,
the global config, `PNPM_CONFIG_TAG`, and `--config.tag`, and threads it
as `defaultTag` into `parseWantedDependencies` (installSome.ts) and the
resolution context (createResolutionContext.ts).
`Config` now carries `tag`, read from the same layers, with
`Config::default_tag` falling back to `latest`. A brand-new `add` with no
version resolves a non-default tag the way an explicit `add <pkg>@<tag>`
does, so the picked version is also locked. A `jsr:` add and the install
resolver take the same default. `dlx`, `add --config`, `update --latest`,
and `outdated` keep `latest`, as they do in v11.
Tested with e2e tests for the yaml setting, `--config.tag`, and a
version-less `npm:` alias, each seen to fail with `default_tag` forced to
`latest`, plus config unit tests for apply, override, reset, and the
resolved projection.
Part of pnpm/tasks#191
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
