fix: add adv->setName, add periodic health check to diagnose invisible BLE device

src/ble_midi_transport.cpp

@@ -95,6 +95,7 @@ bool BleMidiTransport::begin() {
     NimBLEAdvertising* adv = NimBLEDevice::getAdvertising();
     adv->addServiceUUID(BLE_MIDI_SERVICE_UUID);
     adv->setScanResponse(true);
+    adv->setName("JOC Midi");
     adv->start();
 
     initialized = true;
@@ -104,6 +105,13 @@ bool BleMidiTransport::begin() {
 
 void BleMidiTransport::update() {
     client_connected = device_connected;
+    static unsigned long last_report = 0;
+    if (millis() - last_report > 15000) {
+        last_report = millis();
+        NimBLEAdvertising* adv = NimBLEDevice::getAdvertising();
+        Serial.printf("[BLE] Health: connected=%d advertising=%d initialized=%d\n",
+            device_connected, adv ? adv->isAdvertising() : 0, initialized);
+    }
 }
 
 void BleMidiTransport::on_midi_receive(std::function<void(const MidiEvent&)> callback) {