Add HW revision to mDNS for updates

src/lib/config.cpp

@@ -717,3 +717,11 @@ void setupFrontlight()
   flArray.allOFF();
 }
 #endif
+
+String getHwRev() {
+  #ifndef HW_REV
+    return "REV_0";
+  #else
+    return HW_REV;
+  #endif
+}

src/lib/config.hpp

@@ -63,3 +63,4 @@ void improv_send_response(std::vector<uint8_t> &response);
 void improv_set_error(improv::Error error);
 
 void WiFiEvent(WiFiEvent_t event, WiFiEventInfo_t info);
+String getHwRev();

src/lib/webserver.cpp

@@ -94,6 +94,7 @@ void setupWebserver() {
     MDNS.addServiceTxt("http", "tcp", "model", "BTClock");
     MDNS.addServiceTxt("http", "tcp", "version", "3.0");
     MDNS.addServiceTxt("http", "tcp", "rev", GIT_REV);
+    MDNS.addServiceTxt("http", "tcp", "hw_rev", getHwRev());
   }
 
   xTaskCreate(eventSourceTask, "eventSourceTask", 4096, NULL, tskIDLE_PRIORITY,