PITCH/RATE deck: Rate and Pitch knobs compounded into one read increment, on a three-state commit predicate and payload v16

src/core/instrument/map/sample_map.cpp

@@ -237,6 +237,8 @@ PlayParams resolvePlay(const PlaySeconds& stored, int sampleRate) {
     out.trigger = stored.trigger;                        // fraction, unchanged
     out.trigAhd = resolveAhd(stored.trigAhd);
     out.pitchEngine = stored.pitchEngine;
+    out.playRate               = stored.playRate;             // a ratio, rate-free
+    out.pitchOffsetSemitones   = stored.pitchOffsetSemitones; // semitones, rate-free
     out.pitchEnv.enabled       = stored.pitchEnv.enabled;
     out.pitchEnv.peakSemitones = stored.pitchEnv.peakSemitones;  // depth, not a time
     out.pitchEnv.shape         = resolveAhd(stored.pitchEnv.shape);