Manually restart BLE advertising after disconnect to prevent stack freeze

Replaced use of `restartOnDisconnect(true)` with explicit (existing) manual re-advertising logic.
This avoids Bluetooth stack instability caused by overlapping advertising state,
Changes:
- Added explicit `Bluefruit.Advertising.stop()` and data clears in `startAdv()`
- Disabled automatic restart with `restartOnDisconnect(false)`
- Re-advertising now fully handled in `checkRecvFrame()` loop

Tested on: iPhone, Android, Windows, and Chrome – confirmed stable reconnects and name visibility.

src/helpers/nrf52/SerialBLEInterface.cpp

@@ -18,6 +18,10 @@ void SerialBLEInterface::begin(const char* device_name, uint32_t pin_code) {
 }
 
 void SerialBLEInterface::startAdv() {
+  Bluefruit.Advertising.stop(); // always clean restart
+  Bluefruit.Advertising.clearData(); // clear advertising data
+  Bluefruit.ScanResponse.clearData(); // clear scan response data
+  
   // Advertising packet
   Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
   Bluefruit.Advertising.addTxPower();
@@ -27,7 +31,7 @@ void SerialBLEInterface::startAdv() {
 
   // Secondary Scan Response packet (optional)
   // Since there is no room for 'Name' in Advertising packet
-  // Bluefruit.ScanResponse.addName();
+  Bluefruit.ScanResponse.addName();
 
   /* Start Advertising
    * - Enable auto advertising if disconnected
@@ -38,7 +42,7 @@ void SerialBLEInterface::startAdv() {
    * For recommended advertising interval
    * https://developer.apple.com/library/content/qa/qa1931/_index.html   
    */
-  Bluefruit.Advertising.restartOnDisconnect(true);
+  Bluefruit.Advertising.restartOnDisconnect(false); // don't restart automatically as already beeing done in checkRecvFrame()
   Bluefruit.Advertising.setInterval(32, 244);    // in unit of 0.625 ms
   Bluefruit.Advertising.setFastTimeout(30);      // number of seconds in fast mode
   Bluefruit.Advertising.start(0);                // 0 = Don't stop advertising after n seconds