StorageDegraded
Storage backend reported a persistent I/O failure (disk full, permission denied, locked database, etc.) and the engine has dropped into degraded mode. Subsequent storage writes are skipped for the remainder of the session; in-memory state continues to flow on RadioClient.packets, RadioClient.nodes, and RadioClient.events so the user-visible session is preserved, but nothing is written to disk until the next RadioClient.connect.
Emitted at most once per session. Subscribers should surface a "your session is not being persisted" warning to the user; the underlying cause is in reason.
See docs/architecture/storage.md for the rationale and the full list of operations that the engine attempts.
Parameters
a short human-readable description of the underlying failure