Update Ableton MIDI exporter and add comprehensive test suite

src/lib/exporters/ableton/midi.ts

@@ -45,17 +45,21 @@ export function buildMidiClipEnvelopes(
   let previousValue = 0;
   let eventCount = 0;
 
-  events.forEach((event) => {
+  events.toSorted((a, b) => a.position - b.position).forEach((event) => {
     const value = decodeChannelPressure(event);
     if (value === undefined) {
       return;
     }
 
+    eventCount++;
+    if (value === previousValue) {
+      return;
+    }
+
     const time = event.position / 96;
     points.push({ time, value: previousValue });
     points.push({ time, value });
     previousValue = value;
-    eventCount++;
   });
 
   if (eventCount === 0) {