[](https://jxnl.co/writing/2025/08/29/context-engineering-slash-commands-subagents/#__codelineno-2-1)Tests A, B, C are failing
[](https://jxnl.co/writing/2025/08/29/context-engineering-slash-commands-subagents/#__codelineno-2-2)Root cause is in refund.py, introduced by PR #123
[](https://jxnl.co/writing/2025/08/29/context-engineering-slash-commands-subagents/#__codelineno-2-3)Suggested fix: restore the None guard