feat: sustain (CC64), modulation (CC1), pitch bend for MIDI keyboard

- Add controllerChange forwarder for all CC messages (cmd 0xB)
- Add pitchBend method to SonicSF + MIDI handler (cmd 0xE)
- CCs routed to _synthInstance.controllerChange(ch, cc, val)
- Pitch bend routed to _synthInstance.pitchBend(ch, 14bit-val)

app/static/js/services/soundfontPlayer.js

@@ -154,6 +154,13 @@
             return { ..._channels[channel] };
         },
 
+        pitchBend: function (channel, value) {
+            if (channel < 0 || channel > 15) return;
+            if (_initialized && _synthInstance) {
+                try { _synthInstance.pitchBend(channel, value); } catch (e) {}
+            }
+        },
+
         playNote: function (note, velocity, durationMs, startTime, program, destinationNode, channel, synthEngine) {
             if (_initialized && _synthInstance) {
                 this._playNoteSpessa(note, velocity, durationMs, startTime, program, channel, synthEngine);