Update Ableton MIDI exporter to support locked envelopes and improve robustness

tests/ableton-midi.test.ts

@@ -83,14 +83,18 @@ test('decodes only the captured EP Channel Pressure record shape', () => {
 });
 
 test('builds native Live 10 Channel Pressure steps with raw values', () => {
+  const controllerTargets = {
+    'ControllerTargets.129': { '@Id': 45123, LockEnvelope: { '@Value': 0 } },
+  };
   const envelopes = buildMidiClipEnvelopes(
     [midiEvent(192, 2, 20), midiEvent(96, 2, 75), midiEvent(96, 2, 20)],
-    { 'ControllerTargets.129': { '@Id': 45123 } },
+    controllerTargets,
   );
   const envelope = envelopes[0];
   const events = envelope.Automation.Events.FloatEvent;
 
   assert.equal(envelope.EnvelopeTarget.PointeeId['@Value'], 45123);
+  assert.equal(controllerTargets['ControllerTargets.129'].LockEnvelope['@Value'], 1);
   assert.deepEqual(
     events.map((event: any) => [event['@Time'], event['@Value']]),
     [