Investigate and possibly implement real-time tracing: qb-blackbox { --pid <PID> | --command <cmd> }

Currently, there seems to be an opportunity to get on-the-fly stream of messages
temporarily hitting blackbox, enabler being on-disk materialized files.

This would also give an opportunity for a deepest look into the run possible,
beside mere debugging/stracing/probing, which is rather cumbersome for
not so isolated observations.