feat: factory reset in LCD settings menu

Scroll to the last item in Setup menu to see '>> FACTORY RESET <<'.
Press S to execute: clears all NV settings, shows confirmation,
beeps, and returns to home screen.

Accessible both from LCD (Setup menu) and serial ('factory reset').

Author: ImNoahDev

src/main.c

@@ -735,8 +735,24 @@ static int32_t Main_Work(void) {
 
 		// Leave setup
 		if (keyspressed & KEY_S) {
+			if (Setup_isFactoryResetItem(selected)) {
+				// Factory reset from UI
+				NV_FactoryReset();
+				Reflow_ValidateNV();
+				Reflow_LoadCustomProfiles();
+				LCD_FB_Clear();
+				len = snprintf(buf, sizeof(buf), "FACTORY RESET OK");
+				LCD_disp_str((uint8_t*)buf, len, 13, 28, FONT6X6);
+				LCD_FB_Update();
+				Buzzer_Beep(BUZZ_1KHZ, 255, TICKS_MS(100));
+				// Brief pause so user sees the message
+				int wait = 20; // ~2 seconds at 100ms ticks
+				while (wait-- > 0) { retval = TICKS_MS(100); }
+				mode = MAIN_HOME;
+				Reflow_SetMode(REFLOW_STANDBY);
+				retval = 0;
 			// If on bang-bang rows and bang-bang is ON, go to BB Tune
-			if (NV_GetConfig(REFLOW_BANGBANG_MODE) && selected >= 7 && selected <= 9) {
+			} else if (NV_GetConfig(REFLOW_BANGBANG_MODE) && selected >= 7 && selected <= 9) {
 				mode = MAIN_BBTUNE;
 				Reflow_SetMode(REFLOW_STANDBY);
 				retval = 0;

src/setup.c

@@ -48,9 +48,14 @@ static setupMenuStruct setupmenu[] = {
 };
 
 #define NUM_SETUP_ITEMS (sizeof(setupmenu) / sizeof(setupmenu[0]))
+#define FACTORY_RESET_IDX NUM_SETUP_ITEMS  // Virtual item after all real items
 
 int Setup_getNumItems(void) {
-	return NUM_SETUP_ITEMS;
+	return NUM_SETUP_ITEMS + 1; // +1 for factory reset
+}
+
+int Setup_isFactoryResetItem(int item) {
+	return item == FACTORY_RESET_IDX;
 }
 
 int _getRawValue(int item) {
@@ -75,6 +80,7 @@ void Setup_setRealValue(int item, float value) {
 }
 
 void Setup_increaseValue(int item, int amount) {
+	if (item >= (int)NUM_SETUP_ITEMS) return; // Factory reset item — no value
 	int curval = _getRawValue(item) + amount;
 	int maxval = setupmenu[item].maxval;
 	if(curval > maxval)
@@ -83,6 +89,7 @@ void Setup_increaseValue(int item, int amount) {
 }
 
 void Setup_decreaseValue(int item, int amount) {
+	if (item >= (int)NUM_SETUP_ITEMS) return; // Factory reset item — no value
 	int curval = _getRawValue(item) - amount;
 	int minval = setupmenu[item].minval;
 	if(curval < minval)
@@ -95,6 +102,9 @@ void Setup_printFormattedValue(int item) {
 }
 
 int Setup_snprintFormattedValue(char* buf, int n, int item) {
+	if (item >= (int)NUM_SETUP_ITEMS) {
+		return snprintf(buf, n, ">> FACTORY RESET <<");
+	}
 	int curval = _getRawValue(item);
 	int minval = setupmenu[item].minval;
 	int maxval = setupmenu[item].maxval;

src/setup.h

@@ -20,5 +20,6 @@ void Setup_increaseValue(int item, int amount);
 void Setup_decreaseValue(int item, int amount);
 void Setup_printFormattedValue(int item);
 int Setup_snprintFormattedValue(char* buf, int n, int item);
+int Setup_isFactoryResetItem(int item);
 
 #endif /* SETUP_H_ */