fix: wire positions on zoom, MIDI import, envelope release min

- Fix wires not recalculating positions on zoom until panning
- Add MIDI file import button to Piano Roll (parses .mid files)
- Allow envelope release to go to 0 (was clamped at 0.001)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/engine/moduleRegistry.js

@@ -117,7 +117,7 @@ defineModule('envelope', {
     attack: { type: 'knob', min: 0.001, max: 4, default: 0.01, unit: 's', label: 'Attack' },
     decay: { type: 'knob', min: 0.001, max: 4, default: 0.2, unit: 's', label: 'Decay' },
     sustain: { type: 'knob', min: 0, max: 1, default: 0.5, unit: '', label: 'Sustain' },
-    release: { type: 'knob', min: 0.001, max: 8, default: 0.5, unit: 's', label: 'Release' },
+    release: { type: 'knob', min: 0, max: 8, default: 0.5, unit: 's', label: 'Release' },
   },
 });