Subpoena: Trace-native testing for OpenTelemetry

Field notes

An invariant is a TraceQL query stored in a file and reused across unit tests, integration checks against a collector and Tempo, and Grafana production alert rules; a test checks that the copies remain aligned. For process evidence, the project describes an eBPF observer keyed to session cgroups and trace IDs, with argument correlation as a fallback. Absence checks distinguish Pass, Fail, and Inconclusive, and treat Inconclusive as failure by default.