A plain ``profile=None`` default could not tell "caller named the actor"
from "read the card" — an unassigned card is a legitimate None actor, and
the row re-read would silently kick back in for it. Use a module sentinel
so only callers that did not pass an actor fall back to the card row.
Trims the salvaged test file to two invariants in the existing review
lifecycle suite: the never-claimed handoff names the implementer (red on
main) and an unassigned card's synthesized run keeps ``profile=NULL``.
teknium1
616a3ce036