This PR overhauls `pnpm env` use to route through pnpm's own install machinery instead of maintaining a parallel code path with manual symlink/shim/hardlink logic.
```
pnpm env use -g <version>
```
now runs:
```
pnpm add --global node@runtime:<version>
```
via `@pnpm/exec.pnpm-cli-runner`. All manual symlink, hardlink, and cmd-shim code in `envUse.ts` is gone (~1000 lines removed across the package).
### Changes
**npm and npx shims on all platforms**
Added `getNodeBinsForCurrentOS(platform)` to `@pnpm/constants`, returning a `Record<string, string>` with the correct relative paths for `node`, `npm`, and `npx` inside a Node.js distribution. `BinaryResolution.bin` is widened from `string` to `string | Record<string, string>` in `@pnpm/resolver-base` and `@pnpm/lockfile.types`, so the node resolver can set all three entries and pnpm's bin-linker creates shims for each automatically.
**Windows npm/npx fix**
`addFilesFromDir` was skipping root-level `node_modules/` (to avoid storing a package's own dependencies), which stripped the bundled `npm` from Node.js Windows zip archives. Added an `includeNodeModules` option and enabled it from the binary fetcher so Windows distributions keep their full contents.
**Removed subcommands**
`pnpm env add` and `pnpm env remove` are removed. `pnpm env use` handles both installing and activating a version. `pnpm env list` now always lists remote versions (the `--remote` flag is no longer required, though it is kept for backwards compatibility).
**musl support**
On Alpine Linux and other musl-based systems, the musl variant of Node.js is automatically downloaded from [unofficial-builds.nodejs.org](https://unofficial-builds.nodejs.org).
