Fix USB MIDI, add LED startup animation, improve logging

- Use ArduinoUSBMIDI library for proper USB MIDI device recognition
- Add LED startup colour cycle (red, green, blue, yellow, magenta, cyan, white)
- Add comprehensive console logging for all MIDI in/out and switch events
- Log unmapped MIDI messages

include/midi_transport.h

@@ -15,10 +15,10 @@ struct MidiEvent {
         SYSEX
     } type;
     
-    uint8_t channel;      // MIDI channel (1-16)
-    uint8_t data1;         // Note number or CC number
-    uint8_t data2;         // Velocity or CC value
-    uint32_t timestamp;   // Event timestamp
+    uint8_t channel;
+    uint8_t data1;
+    uint8_t data2;
+    uint32_t timestamp;
 };
 
 class UsbMidiTransport {
@@ -29,17 +29,15 @@ public:
     bool begin();
     void update();
     
-    // Callback registration
     void on_midi_receive(std::function<void(const MidiEvent&)> callback);
     
-    // Send MIDI
     void send_note_on(uint8_t channel, uint8_t note, uint8_t velocity);
     void send_note_off(uint8_t channel, uint8_t note, uint8_t velocity);
     void send_cc(uint8_t channel, uint8_t cc, uint8_t value);
     
+    bool is_connected();
+    
 private:
     std::function<void(const MidiEvent&)> receive_callback;
     bool initialized;
-    
-    void parse_midi_packet(const uint8_t* buffer, uint32_t size, MidiEvent& event);
 };