Wrap Stage 7.1 participant RPCs and add a version-aware ParticipantCache
with batch hydration helpers for agents and services.
Co-authored-by: Cursor <cursoragent@cursor.com>
Provide a standalone agent client for l-ai-chat with service-token auth, safe at-least-once subscriptions, ordered cumulative ACK tracking, and self-contained gRPC fake tests.
Co-authored-by: Cursor <cursoragent@cursor.com>