AgentTeams: idle notifications spam every turn-end with no content change

Observed

Every teammate turn fires a {"type":"idle_notification","from":"<name>","timestamp":"...","idleReason":"available"} to the lead, whether or not the teammate produced new output.

In a 2-hour session with 4 teammates, I counted 40+ idle notifications with no new information — just idleReason: available.

Impact

• Lead burns turns acknowledging ("noted") pings that contain no signal.
• Masks genuine state changes: a real "teammate finished task" message and "teammate idled after no-op" look the same at a glance.
• Linear cost with team size × turn count.

Suggested behavior

Emit idle only when:

• Teammate produced visible output this turn (TaskUpdate, SendMessage, file edit)
• Or teammate transitions from a non-idle state (working → idle for the first time after task completion)

Don't emit on subsequent no-op turns.

Alternative: collapse consecutive idle pings from the same teammate into one.

Env

Claude Code CLI (macOS). CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1. Skill: swarm-team.