docs: add explanatory comment to npm workspace member fix

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Strum355

src/providers/javascript_npm.js

@@ -19,6 +19,10 @@ export default class Javascript_npm extends Base_javascript {
 	}
 
 	_buildDependencyTree(includeTransitive, opts = {}) {
+		// npm ls --json returns a single tree rooted at the workspace root.
+		// When analyzing a workspace member, its deps are nested under the
+		// root's dependencies keyed by the member name — extract that subtree
+		// so downstream analysis sees only the member's dependencies.
 		const tree = super._buildDependencyTree(includeTransitive, opts);
 		const memberName = this._getManifest().name;
 		if (tree.name === memberName) {