Module storage 

Metrics persistence — save, load, and list session metrics from disk.

Functions

list_all_metrics

List all session summaries by scanning the sessions directory. Reads each session_metrics.json and extracts summary fields.

load_metrics

Load session metrics from session_metrics.json in a session directory.

save_metrics

Incrementally write session metrics to session_metrics.json. Overwrites the file on each call — safe for per-turn writes.

try_load_metrics

Try to load session metrics, returning None if the file doesn’t exist.