Version column in tasks table with WHERE id=? AND version=? guard. Conflict detection in TaskBoardTab. error-classifier.ts: 6 error types with actionable messages and retry logic. UsageMeter.svelte.
Phase 2: bttask CLI (Python, SQLite) — task management with role-based visibility. Kanban board view. Manager/Architect can create tasks, Tier 2 agents receive tasks via btmsg only. Phase 3: GroupAgentConfig in groups.json + Rust backend. GroupAgentsPanel Svelte component above ProjectGrid with status dots, role icons, unread badges, start/stop buttons. Phase 4: btmsg Rust bridge (btmsg.rs) — read/write access to btmsg.db. 6 Tauri commands for agent status, messages, and history. GroupAgentsPanel polls btmsg.db every 5s for live status updates.
