When hierarchical pins connect to global power nets, the multichannel
repeat-layout tool incorrectly reports a topology mismatch. The net
isomorphism algorithm treats global nets as channel-internal, causing
two failures: connection counts differ when global net pads are shared
with external components, and net-consistency checks flag false
contradictions between channels. The fix identifies nets whose
footprints fall outside the channel's footprint set and excludes them
from connection building and net-consistency checks. Global power rails
do not define internal channel routing topology, so this is correct.
Adds a QA regression test and reproduction board.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/21739
Seth Hillbrand
2d6db2ffc4