Disable battery and cal state update in browser mode

nanovna.h

@@ -1458,6 +1458,7 @@ bool ui_process_listen_lever(void);
 void refresh_sweep_menu(int i);
 void save_to_sd(int mask);
 void drawMessageBox(const char *header, char *text, uint32_t delay);
+bool isFullScreenMode(void);
 
 // Irq operation process set
 #define OP_NONE       0x00

plot.c

@@ -1252,6 +1252,7 @@ draw_all_cells(bool flush_markmap)
 void
 draw_all(bool flush)
 {
+  if (isFullScreenMode()) return;
 #ifdef __LEVEL_METER__
   level_text[0] = 0;    // Clear level text
 #endif

ui.c

@@ -155,6 +155,14 @@ static void menu_move_back(bool leave_ui);
 static void draw_button(uint16_t x, uint16_t y, uint16_t w, uint16_t h, ui_button_t *b);
 //static const menuitem_t menu_marker_type[];
 
+bool isFullScreenMode(void) {
+#ifdef __SD_FILE_BROWSER__
+  return ui_mode == UI_BROWSER;
+#else
+  return false;
+#endif
+}
+
 static int btn_check(void)
 {
   systime_t ticks;