instrument: spline EGs — hard points on the one shared spline, a drawn contour per envelope beside its staged state, payload v13

src/core/instrument/map/sample_map.cpp

@@ -256,6 +256,16 @@ PlayParams resolvePlay(const PlaySeconds& stored, int sampleRate) {
     out.filter.env.decayCurve    = stored.filter.env.decayCurve;
     out.filter.env.releaseCurve  = stored.filter.env.releaseCurve;
     out.filter.trigEnv           = resolveAhd(stored.filter.trigEnv);
+    // The three drawn contours are normalized over the sample's own length, so no rate resolves
+    // them — they carry through verbatim, which is also what makes a different-length capture
+    // replay the same shape proportionally.
+    out.ampSpline        = stored.ampSpline;
+    out.pitchSpline  = stored.pitchSpline;
+    out.filterSpline = stored.filterSpline;
+    // Gate is unavailable while any EG is drawn — see splineActive (play_params.h) for why.
+    // The editor refuses the Gate segment for the same reason; enforcing it HERE as well is
+    // what keeps a hand-edited or downgraded blob from reaching the engine as Gate + spline.
+    if (splineActive(stored)) out.playMode = PlayMode::Trigger;
     return out;
 }