Summary

• rwx sandbox list now automatically removes expired sandboxes from local storage instead of requiring a --sync flag
• Expired sandboxes (completed, 404, or 410) are pruned from storage and excluded from results
• Unknown-status sandboxes (e.g. network errors) are kept in storage and results

Test plan

• Unit tests for pruning expired sandboxes from storage and results
• Unit tests for pruning 404/410 sandboxes
• Unit tests for retaining unknown-status sandboxes