A :logger handler that turns every BEAM process crash into an Event.

The BEAM puts :crash_reason — {reason, stacktrace} — into Logger metadata for every crash a supervisor reports. Attaching here captures the whole otp Domain with no call sites in application code, which is what makes it the cheapest of the crash domains to collect.

This runs inside the crashing process. It extracts and hands off; the work happens in Bellwether.Reporter.