instrument: the filter's velocity depth knob returns and multiplies the bipolar curve; the pre-v12 lift is a pure domain re-tag

src/core/instrument/engine/live_params.cpp

@@ -9,6 +9,7 @@ LiveValues foldLive(const PlayParams& params) {
     LiveValues v;
     v.filterSettings = params.filter.settings;
     v.filterModAmount = params.filter.modAmount;
+    v.filterVelAmount = params.filter.velAmount;
     v.filterKeyTrack = params.filter.keyTrack;
     v.filterEnv = params.filter.env;
     v.filterAhd = params.filter.trigEnv;