Petri Net Reduction

Removes the scaffolding from an accepting Petri net without changing what it does. A converted or discovered net carries a place per sequence flow and a silent transition per gateway — structure the construction needed and the process does not. Reduction fuses it away, and the promise is exact: the reduced net produces the same sequences of activities, and accepts the same ones. That is checked on every build by enumerating both nets' languages with the play-out plugin.