Service both VST3 parameter channels, and promote pitch key-track and Trigger length so all 44 ids issue

The SDK's own single-component sample drains inputParameterChanges in
process() and implements setParamNormalized; automation was reading the
GUI channel alone. The audio thread now patches a block it solely owns.

tests/test_bake_render.cpp

@@ -210,7 +210,7 @@ int main() {
         {
             PlayParams slow = s.play;
             slow.trigAhd.attackFrames = 900;
-            block.publish(instrument::engine::foldLive(slow));
+            block.publish(instrument::engine::foldLive(slow, s.keyTrack));
         }
 
         const BakePlan plan = planOf(/*total=*/1000, /*noteOn=*/0, /*noteOff=*/1000);