[wifi] Leave the AP before an LN882x reboots (#20176)

esphome/components/wifi/wifi_component.h

@@ -506,6 +506,9 @@ class WiFiComponent final : public Component {
   // (In most use cases you won't need these)
   /// Setup WiFi interface.
   void setup() override;
+#ifdef USE_LN882X
+  void on_powerdown() override;
+#endif
   void start();
   void dump_config() override;
   void restart_adapter();

esphome/components/wifi/wifi_component_libretiny.cpp

@@ -800,6 +800,17 @@ bool WiFiComponent::wifi_start_ap_(const WiFiAP &ap) {
 network::IPAddress WiFiComponent::wifi_soft_ap_ip() { return {WiFi.softAPIP()}; }
 #endif  // USE_WIFI_AP
 
+#ifdef USE_LN882X
+void WiFiComponent::on_powerdown() {
+  // Leave the AP so it no longer holds the association when we come back.
+  if (WiFi.status() != WL_CONNECTED)  // associated, even before DHCP has finished
+    return;
+  ESP_LOGD(TAG, "Disconnecting before powerdown");
+  wifi_sta_disconnect();  // not WiFi.disconnect(): it frees the SSID its event handlers read
+  delay(100);             // NOLINT: once per reboot or deep sleep, lets the deauth go out
+}
+#endif
+
 bool WiFiComponent::wifi_disconnect_() {
   // Reset state first so disconnect events aren't ignored
   // and wifi_sta_connect_status_() returns IDLE instead of CONNECTING