Resolve native-preview tsdk symlinks before locating platform package

[Copilot]

pnpm can install @typescript/native-preview as a symlink into its virtual store. The extension followed the configured path to read package.json, but derived the platform package path from the unresolved symlink location, which fails when dependencies are not hoisted.

• tsdk resolution

  • Resolve file-based tsdk URIs through realpath before looking for sibling platform packages.
  • Preserve the existing behavior for non-file URIs and paths where realpath fails.

• pnpm virtual store support

  • Allows settings like:

    {
      "typescript.native-preview.tsdk": "./node_modules/@typescript/native-preview"
    }

    to resolve the executable from the real package location under .pnpm/.../node_modules/@typescript/.

[Copilot]

Pull request overview

This PR fixes VS Code native-preview TSDK executable discovery when @typescript/native-preview is installed as a symlink (notably via pnpm’s virtual store), by resolving file-based TSDK locations through realpath before deriving the sibling platform-package path.

Changes:

• Resolve workspaceResolve(tsdkPath) through a new realpathUri helper before searching for package.json and platform package siblings.
• Preserve existing behavior for non-file URI schemes and for cases where realpath fails (falls back to the original URI).

Show a summary per file

File	Description
_extension/src/util.ts	Resolve file-based TSDK URIs via realpath before locating the platform package so pnpm symlink installs work when deps aren’t hoisted.

Review details

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• Review effort level: Low