- Add WebSocket heartbeat ping every 30s to detect stale connections - Add completer guards to prevent double-completion errors in: - music_assistant_api.dart (connection completers) - music_assistant_provider.dart (registration completers) - player_provider.dart (registration completers) - Add heartbeatInterval constant to Timings class - Update AUDIT_PROGRESS.md with Phase 8 status 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>