adjust default log, pick and config locations. renotify on critical only, make user sessions persistem

hbd/server/users.py

@@ -226,3 +226,17 @@ def _purge_expired_sessions() -> None:
     expired = [t for t, s in list(_sessions.items()) if s["expires"] < now]
     for t in expired:
         del _sessions[t]
+
+
+def save_sessions() -> dict:
+    """Return a snapshot of non-expired sessions suitable for pickling."""
+    _purge_expired_sessions()
+    return dict(_sessions)
+
+
+def load_sessions(snapshot: dict) -> None:
+    """Restore sessions from a pickled snapshot, dropping any that have expired."""
+    global _sessions
+    now = time.time()
+    _sessions = {t: s for t, s in snapshot.items() if s.get("expires", 0) > now}
+    logger.debug("Restored %d session(s) from pickle", len(_sessions))