A production-only 500 note should name the boundary that changed

A production debugging note about recording URL, deploy id, runtime, request id, and local/production differences.

A production-only 500 report is most useful when it names the changed boundary: env var, runtime, region, cookie domain, callback URL, database state, or cache. “Works locally” is a lead, not a packet. Exact URL, deploy id, request id, runtime, and one local comparison usually save the first debugging hour.