Add background task that subscribes to kind 31922/31923 events
from relays and processes them into the local database. Starts
15s after NostrClient connects (sequenced after publish client).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Start a publish-only NostrClient as a background task (10s delay
for nostrclient readiness). Graceful degradation: if nostrclient
is unavailable, events extension continues without Nostr publishing.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
