Feature: Add pnpm workspace hover

[Stanzilla]

This implements #302736

[Copilot]

Pull request overview

Adds npm package metadata hovers for pnpm-workspace.yaml catalog entries by reusing the npm extension’s existing registry/npm view lookup logic.

Changes:

• Register a new hover provider for pnpm-workspace.yaml in both desktop and browser entrypoints.
• Add PnpmWorkspaceHoverProvider to show npm package metadata when hovering catalog keys/versions.
• Refactor npm package metadata fetching/formatting into a shared NpmPackageInfoProvider used by both package.json and pnpm workspace hovers.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
extensions/npm/src/npmMain.ts	Registers pnpm workspace hover provider in the desktop extension activation.
extensions/npm/src/npmBrowserMain.ts	Registers pnpm workspace hover provider in the web extension activation.
extensions/npm/src/features/pnpmWorkspaceHover.ts	Implements YAML-aware hover provider for catalog / catalogs entries.
extensions/npm/src/features/packageJSONContribution.ts	Refactors to reuse shared npm package metadata provider.
extensions/npm/src/features/packageInfo.ts	New shared provider for npm package metadata lookup and hover markdown formatting.
extensions/npm/package.json	Extends activation events to include YAML / pnpm workspace scenarios.

---

You can also share your feedback on Copilot code review. Take the survey.

[Stanzilla]

Added a follow-up commit with focused coverage for the pnpm workspace hover path.

It extracts the pnpm workspace target resolution into a small helper and adds unit tests covering:

• top-level catalog entries
• nested catalogs entries
• ignoring unrelated sections / section headers

I also recompiled the extension and re-verified the hover against a real pnpm-workspace.yaml in an extension-development host.