Current-behaviour pin for the declared-taps design: a producer node
with a non-empty output and zero out-edges compiles, bootstraps, and
runs — its per-cycle output silently discarded — observably identical
to the same graph with the producer removed. This is the exact shape
of an unbound declared tap (a study wire left un-recorded in a sweep),
and it establishes that the engine already tolerates it: no DCE is
needed for correctness, because check_ports_connected gates only input
slots and the Kahn sort emits a no-out-edge node as a valid sink. The
build-time-elision soundness the tap mechanism will rely on.
refs #282
claude
b11bcb6202