heartbeat.model 覆盖生效，心跳任务可独立于会话模型

• Heartbeat polling is enabled and you maintain HEARTBEAT.md tasks.
• You can modify runtime model config and observe heartbeat execution logs.

1. Set a dedicated lightweight model under heartbeat.model while keeping session default unchanged.
2. Trigger a heartbeat cycle with deterministic checklist tasks.
3. Inspect execution logs or status card to confirm heartbeat turn uses configured override model.
4. Compare cost/latency before and after model split for at least one business day.
5. Keep escalation rules so urgent heartbeat findings can still hand off to stronger model paths.

• Model override behavior can differ across custom wrappers or legacy configs（需验证）.
• Do not route safety-critical decisions exclusively through smallest models.

This tip is aggregated from community/public sources and preserved with attribution.