Cherry-picked via 3-way apply onto stage HEAD.
Resolved workspace.js conflict: kept master's #2716 sessionId-capture
stale-session guard (closure-scoped sessionId check after await), AND
added PR's renderSessionArtifacts() call to refresh the new Artifacts
tab when the file tree updates. Wrapped in typeof check for defense.
Co-authored-by: AJV20 <abdielvc@me.com>