dashboard: reduce status indicator redraws

firmware/esp32-s3-dashboard/esp32-s3-dashboard.ino

@@ -61,6 +61,8 @@ static String last_battery_soc_text;
 static String last_inside_temp_text;
 static String last_outside_temp_text;
 static String last_system_status_text;
+static int last_wifi_bar_count = -1;
+static bool last_cargo_api_ok = false;
 
 static String on_off(bool value)
 {
@@ -117,9 +119,17 @@ static void update_status_icons()
         return;
     }
 
-    lvgl_port_lock(-1);
-
     int bars = wifi_bar_count();
+    bool cargo_ok = status_model.api_ok;
+
+    if (bars == last_wifi_bar_count && cargo_ok == last_cargo_api_ok) {
+        return;
+    }
+
+    last_wifi_bar_count = bars;
+    last_cargo_api_ok = cargo_ok;
+
+    lvgl_port_lock(-1);
 
     for (int i = 0; i < 4; i++) {
         if (wifi_bars_obj[i] == nullptr) {
@@ -135,7 +145,7 @@ static void update_status_icons()
 
     lv_obj_set_style_bg_color(
         cargo_status_dot,
-        status_model.api_ok ? lv_color_hex(0x32D583) : lv_color_hex(0xF97066),
+        cargo_ok ? lv_color_hex(0x32D583) : lv_color_hex(0xF97066),
         0
     );
 
@@ -488,7 +498,7 @@ static void update_system_status_label()
         was_wifi_connected = false;
     }
 
-    if (millis() - last_wifi_label_update_ms < 1000) {
+    if (millis() - last_wifi_label_update_ms < 5000) {
         return;
     }