Add visual MIDI type indicators

- SysEx: ALL LEDs flash white 200ms
- Note: LED 0 flashes red 100ms
- CC: LED 1 flashes green 100ms
- Helps diagnose what MIDI arrives without serial

src/app_task.cpp

@@ -46,16 +46,20 @@ void AppTask::process_midi_event(const MidiEvent& event) {
     Serial.printf("[APP] MIDI IN: Type=%d Ch=%d Data1=%d Data2=%d\n",
                   event.type, event.channel, event.data1, event.data2);
 
-    // Flash LED 0 white briefly on ANY MIDI input - visual activity indicator
-    // (visible without serial when connected to iPad)
-    led_driver->flash_activity();
+    // Visual MIDI type indicator (works without serial on iPad)
+    if (event.type == MidiEvent::SYSEX) {
+        led_driver->flash_all(255, 255, 255, 200);  // SysEx = ALL white
+    } else if (event.type == MidiEvent::NOTE_ON || event.type == MidiEvent::NOTE_OFF) {
+        led_driver->flash_one(0, 255, 0, 0, 100);   // Note = LED 0 red
+    } else if (event.type == MidiEvent::CONTROL_CHANGE) {
+        led_driver->flash_one(1, 0, 255, 0, 100);   // CC = LED 1 green
+    }
     
     if (event.type == MidiEvent::SYSEX) {
         // Cin is encoded in channel for SYSEX packets
         uint8_t cin = event.channel;
         uint8_t packet[3] = {event.data1, event.data2, 0};
         process_sysex_packet(packet, cin);
-        led_driver->flash_sysex();
         return;
     }