Add battery min/max voltage parameter support

examples/companion_radio/ui-orig/UITask.cpp

@@ -149,8 +149,14 @@ void UITask::newMsg(uint8_t path_len, const char* from_name, const char* text, i
 
 void UITask::renderBatteryIndicator(uint16_t batteryMilliVolts) {
   // Convert millivolts to percentage
-  const int minMilliVolts = 3000; // Minimum voltage (e.g., 3.0V)
-  const int maxMilliVolts = 4200; // Maximum voltage (e.g., 4.2V)
+#ifndef BATT_MIN_MILLIVOLTS
+  #define BATT_MIN_MILLIVOLTS 3000
+#endif
+#ifndef BATT_MAX_MILLIVOLTS
+  #define BATT_MAX_MILLIVOLTS 4200
+#endif
+  const int minMilliVolts = BATT_MIN_MILLIVOLTS;
+  const int maxMilliVolts = BATT_MAX_MILLIVOLTS;
   int batteryPercentage = ((batteryMilliVolts - minMilliVolts) * 100) / (maxMilliVolts - minMilliVolts);
   if (batteryPercentage < 0) batteryPercentage = 0; // Clamp to 0%
   if (batteryPercentage > 100) batteryPercentage = 100; // Clamp to 100%