Plugin version tracking gets a fallback for npm-based marketplaces without a git checkout
When Claude Code figures out which version of a plugin's code is installed (by resolving a git commit hash, used for caching), it now handles the case where the plugin's checkout isn't a git repository but comes from an npm-style plugin marketplace. In that case, it falls back to a separate resolver to find a commit-like identifier. A new keepStoredCommit flag also ensures that if neither method can resolve an identifier, a previously stored one isn't discarded.
This prevents plugins installed from npm-based marketplaces from losing their version-tracking information just because they weren't installed via a plain git checkout, and avoids erasing a known-good stored version when a fresh lookup comes up empty.