- Add constants package with IsInternalChannel helper to centralize internal channel checks across agent, channels, and heartbeat services
- Add ToProviderDefs method to ToolRegistry to consolidate tool definition conversion logic used in agent loop and tool loop
- Refactor SubagentTool.Execute to use RunToolLoop for consistent tool execution with iteration tracking
- Remove duplicate inline map definitions and type assertion code throughout codebase
feat(config): add heartbeat interval configuration with default 30 minutes
feat(state): migrate state file from workspace root to state directory
feat(channels): skip internal channels in outbound dispatcher
feat(agent): record last active channel for heartbeat context
refactor(subagent): use configurable default model instead of provider default
Add Slack as a messaging channel using Socket Mode (WebSocket), bringing
the total supported channels to 8. Features include bidirectional
messaging, thread support with per-thread session context, @mention
handling, ack reactions (👀/✅), slash commands,
file/attachment support with Groq Whisper audio transcription, and
allowlist filtering by Slack user ID.
Closes#31
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>