The go-nostr RelayConnect returns immediately after the WebSocket
handshake, but the relay has not yet sent the AUTH challenge. Calling
relay.Auth() right away signs the auth event with an empty challenge
tag, which the Buzz relay rejects with 'auth-required: verification
failed'.
Retry the Auth() call up to 3 times with 1s backoff between attempts,
giving the relay time to deliver the challenge.
Implements a Buzz channel backed by a Nostr relay:
- kind:9 events scoped by "h" tag, "p" tags for mentions
- NIP-42 (kind:22242) auth before subscription
- optional threaded replies via "e" tag
- registered as config.ChannelBuzz with BuzzSettings
