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/App.jsx

@@ -255,7 +255,7 @@ export default function App() {
           </svg>
 
           {/* Wire layer (behind modules, uses getBoundingClientRect) */}
-          <WireLayer portPositions={portPositions} tempWire={tempWire} containerRef={containerRef} />
+          <WireLayer portPositions={portPositions} tempWire={tempWire} containerRef={containerRef} zoom={state.zoom} camX={state.camX} camY={state.camY} />
 
           {/* Modules container (offset by camera) */}
           <div style={{ position: 'absolute', left: state.camX, top: state.camY, zIndex: 2 }}>