Migration 0034 has the column and the Prisma model did not, so a regenerated
client and the database disagreed.
The extraction comment claimed only a finished reply is accepted while the code
accepts an absent finish_reason. The code is right — failing every call on a
provider that omits an optional field would be a certain outage in exchange for
a case that also requires syntactically complete JSON, and the harm a truncated
reply does is closed on the write side. The prose now states the rule as it is:
a reason that is PRESENT must be `stop`.