{
  "schema": 1,
  "scope": [
    "以下流程与样例由本站设计；样例均为虚构教学输入，参考文件不是产品运行记录。",
    "Workflows and samples are designed for this site. Inputs are fictional teaching material; references are not product execution records."
  ],
  "fictional": true,
  "change": "return a - b -> return a + b",
  "wrong_outputs": [
    -1,
    -3,
    4
  ],
  "fixed_outputs": [
    5,
    -1,
    4
  ],
  "limit": "Zero alone cannot distinguish the versions. Invalid-input handling and floating-point money arithmetic are outside this exercise.",
  "rollback": "Restore add-bug.mjs or reverse the one-line patch."
}