Classify error into 4 buckets (transient / deterministic / stale / unknown) and pick one of 5 actions (retry / switch / fallback / refresh-then-retry / ask-user / skip).
USE WHEN: tool returns non-success, sub-agent `status: closed-failed`, exception escapes, timeout fires, weird partial-success result, ECONNREFUSED / 5xx / 429 / timeout / permission denied / "command not found" / "fail" / "error" / "出错了" / "挂" / "失败".
TRIGGER PHRASES: "出错了", "failed", "挂", "error", "失败", "fail", "permission denied", "command not found", "ECONNREFUSED", "timeout", "挂了", "再试一次", "retry", "这不行", "没用", "fallback", "退路", "不行", "跑不通", "broken".
SKIP WHEN: operation succeeded, error is in user …
