- Add terminated→idle as a valid state transition in AGENT_VALID_TRANSITIONS
- Add resetAgent() method that clears lastError, taskId, and ends heartbeat runs
- Clear lastError automatically when transitioning away from terminated state
- Remove inline heartbeat lifecycle from updateAgentState (moved to resetAgent)
- Add comprehensive tests for state transitions, error clearing, and resetAgent behavior
- Remove blanket block on terminated→any state transitions in agent-store
- Add active and running as valid transitions from terminated state in types
- Update tests to verify terminated→active and terminated→running succeed
- Add tests for invalid terminated transitions (idle, paused) still throwing
- Add 62 tests covering all AgentStore public methods (init, CRUD, state transitions, heartbeats, assignments)
- Test event emissions (agent:created, agent:updated, agent:deleted, agent:heartbeat, agent:stateChanged)
- Test error paths, state transition validation, and concurrency locking
- Verify filesystem persistence across store re-initialization
- Update coverage gaps doc to mark agent-store.ts as covered
