Update Ableton MIDI exporter to support locked envelopes and improve robustness

src/lib/exporters/ableton/midi.ts

@@ -1,6 +1,9 @@
 import type { AblMidiEvent } from '../../transformers/ableton';
 
-export type AbletonMidiControllerTargets = Record<string, { '@Id': number }>;
+export type AbletonMidiControllerTargets = Record<
+  string,
+  { '@Id': number; LockEnvelope?: { '@Value': number | string } }
+>;
 
 type AutomationPoint = {
   time: number;
@@ -36,10 +39,13 @@ export function buildMidiClipEnvelopes(
   events: AblMidiEvent[],
   controllerTargets: AbletonMidiControllerTargets,
 ) {
-  const target = controllerTargets[`ControllerTargets.${CHANNEL_PRESSURE_TARGET}`]?.['@Id'];
-  if (target === undefined) {
+  const target = controllerTargets[`ControllerTargets.${CHANNEL_PRESSURE_TARGET}`];
+  if (!target) {
     return [];
   }
+  if (target.LockEnvelope) {
+    target.LockEnvelope['@Value'] = 1;
+  }
 
   const points: AutomationPoint[] = [{ time: SENTINEL_TIME, value: 0 }];
   let previousValue = 0;
@@ -70,7 +76,7 @@ export function buildMidiClipEnvelopes(
   return [
     {
       '@Id': 0,
-      EnvelopeTarget: { PointeeId: { '@Value': target } },
+      EnvelopeTarget: { PointeeId: { '@Value': target['@Id'] } },
       Automation: {
         Events: { FloatEvent: floatEvents(points) },
         AutomationTransformViewState: {