Add receive queue, subscription management, and event deduplication
to support incoming NIP-52 calendar events from relays.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Stripped-down Nostr client that connects to nostrclient's internal
WebSocket for publishing NIP-52 calendar events. No subscription
capabilities — publish queue only.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
