Improve power saving and payload safety

src/wifi_manager.cpp

@@ -1,5 +1,6 @@
 #include "wifi_manager.h"
 #include <WiFi.h>
+#include <esp_wifi.h>
 
 static Preferences prefs;
 
@@ -43,7 +44,11 @@ bool wifi_connect_sta(const WifiMqttConfig &config, uint32_t timeout_ms) {
   while (WiFi.status() != WL_CONNECTED && millis() - start < timeout_ms) {
     delay(200);
   }
-  return WiFi.status() == WL_CONNECTED;
+  bool connected = WiFi.status() == WL_CONNECTED;
+  if (connected) {
+    esp_wifi_set_ps(WIFI_PS_MIN_MODEM);
+  }
+  return connected;
 }
 
 void wifi_start_ap(const char *ap_ssid, const char *ap_pass) {