MQTT messages. Button anleren, Wifi frontend

src/timesync.h

@@ -196,3 +196,9 @@ bool isValidDateTime(int year, int month, int day, int hour, int minute, int sec
   
   return day <= daysInMonth[month - 1];
 }
+
+uint64_t getCurrentTimestampMs() {
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return (uint64_t)tv.tv_sec * 1000LL + (uint64_t)tv.tv_usec / 1000LL;
+}