What crosses between svc-gw and the app: hello, heartbeats both ways, state
snapshots of envelopes with mock flagged per message, and commands carrying an
idempotency key. TTS utterances are left for when a TTS exists.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DDwfd6Ki8UfG4hK6W5YpJz
mikkeli