fix: stabilize primary ESP-NOW WiFi coexistence

src/helpers/WiFiChannelPolicy.h

@@ -42,5 +42,13 @@ inline uint8_t validEspNowChannelOrDefault(uint8_t stored,
   return isValidEspNowChannel(stored) ? stored : fallback;
 }
 
+// Rewriting an ESP32's current WiFi channel is not a harmless no-op. The
+// driver briefly reconfigures the shared RF path, which can interrupt SoftAP
+// beacons and ESP-NOW receive when a caller repeats the write from a fast main
+// loop. Only request a restore when the primary channel actually moved.
+inline bool espNowChannelRestoreRequired(uint8_t current, uint8_t target) {
+  return current != target;
+}
+
 } // namespace wifi
 } // namespace mesh

src/helpers/WiFiSetupPortal.cpp

@@ -334,10 +334,7 @@ bool WiFiSetupPortal::begin(const char* ap_name, SaveCallback save_callback, voi
   if (!WiFi.softAPConfig(SETUP_IP, SETUP_IP, SETUP_MASK)
       || !WiFi.softAP(impl->ap_name, nullptr,
                       mesh::wifi::accessPointChannel())
-      || esp_wifi_set_protocol(
-             WIFI_IF_AP,
-             mesh::wifi::kProtocolMask)
-             != ESP_OK
+      || mesh::wifi::applyAccessPointProtocolMask() != ESP_OK
       || esp_wifi_set_protocol(
              WIFI_IF_STA,
              mesh::wifi::kProtocolMask)

src/helpers/esp32/ESPNOWRadio.cpp

@@ -129,6 +129,19 @@ void ESPNOWRadio::init() {
     return;
   }
 
+#if defined(MESH_PRIMARY_ESPNOW) && MESH_PRIMARY_ESPNOW
+  // Modem sleep is still required when BLE and infrastructure WiFi coexist,
+  // but unicast/broadcast ESP-NOW frames are not buffered by an access point.
+  // Hold the driver's documented wake reference for the lifetime of this
+  // primary mesh radio so receive stays continuous without disabling the
+  // WiFi/Bluetooth coexistence policy globally.
+  if (esp_wifi_force_wakeup_acquire() != ESP_OK) {
+    ESPNOW_DEBUG_PRINTLN("Error keeping primary ESP-NOW receive awake");
+    esp_now_deinit();
+    return;
+  }
+#endif
+
   esp_wifi_set_max_tx_power(80);  // should be 20dBm
 
   esp_now_register_send_cb(OnDataSent);

src/helpers/esp32/WebConfigServer.cpp

@@ -774,8 +774,8 @@ bool WebConfigServer::startSetupMode(char reply[]) {
       // LR bit set. The driver then reports a healthy SoftAP, but ordinary
       // phones and laptops cannot discover its beacon. A WiFi companion must
       // advertise using the interoperable 2.4 GHz protocol set.
-      const esp_err_t ap_protocol_result = esp_wifi_set_protocol(
-          WIFI_IF_AP, mesh::wifi::kProtocolMask);
+      const esp_err_t ap_protocol_result =
+          mesh::wifi::applyAccessPointProtocolMask();
       const esp_err_t sta_protocol_result = esp_wifi_set_protocol(
           WIFI_IF_STA, mesh::wifi::kProtocolMask);
       if (ap_protocol_result == ESP_OK && sta_protocol_result == ESP_OK) break;
@@ -812,7 +812,10 @@ bool WebConfigServer::startSetupMode(char reply[]) {
   _initial_setup = _wifi_ssid[0] == 0 && node.admin_password[0] != 0;
   _setup_started_at = millis();
   _last_activity = _setup_started_at;
-  WiFi.scanNetworks(true);  // pre-populate the SSID picker
+  // A primary ESP-NOW radio cannot leave its selected channel while scanning.
+  // Ordinary WiFi targets retain the zero-channel all-band scan.
+  WiFi.scanNetworks(true, false, false, 300,
+                    mesh::wifi::stationScanChannel());
 
   sprintf(reply, "WebConfig AP started: join '%s' then open http://%s/", _ap_ssid, ip.toString().c_str());
   return true;
@@ -2329,7 +2332,8 @@ void WebConfigServer::handleScan(AsyncWebServerRequest* req) {
     n = WIFI_SCAN_FAILED;
   }
   if (n == WIFI_SCAN_FAILED) {
-    WiFi.scanNetworks(true);
+    WiFi.scanNetworks(true, false, false, 300,
+                      mesh::wifi::stationScanChannel());
     req->send(200, "application/json", "{\"state\":\"scanning\"}");
     return;
   }

src/helpers/esp32/WiFiRadioPolicy.h

@@ -40,6 +40,11 @@ static constexpr uint8_t kProtocolMask = WIFI_PROTOCOL_11B
     | WIFI_PROTOCOL_11G | WIFI_PROTOCOL_11N;
 #endif
 
+// LR is private to ESP-NOW on the station interface. A setup SoftAP must keep
+// an ordinary b/g/n protocol bitmap so phones and laptops can discover it.
+static constexpr uint8_t kAccessPointProtocolMask = WIFI_PROTOCOL_11B
+    | WIFI_PROTOCOL_11G | WIFI_PROTOCOL_11N;
+
 #if defined(MESH_PRIMARY_ESPNOW) && MESH_PRIMARY_ESPNOW
 struct EspNowBootChannelState {
   bool loaded;
@@ -98,6 +103,10 @@ inline esp_err_t applyProtocolMask(wifi_interface_t interface_id) {
   return esp_wifi_set_protocol(interface_id, kProtocolMask);
 }
 
+inline esp_err_t applyAccessPointProtocolMask() {
+  return esp_wifi_set_protocol(WIFI_IF_AP, kAccessPointProtocolMask);
+}
+
 // An ESP-NOW radio and an associated station cannot occupy different channels.
 // Full Companion therefore keeps both its setup AP and any infrastructure-WiFi
 // association on the mesh channel. Passing zero on ordinary targets preserves
@@ -118,12 +127,18 @@ inline uint8_t stationScanChannel() {
 
 inline esp_err_t restoreEspNowChannel() {
   if (!kKeepEspNowRadioRunning) return ESP_OK;
+  const uint8_t target = activeEspNowChannel();
+  uint8_t current = 0;
+  wifi_second_chan_t secondary = WIFI_SECOND_CHAN_NONE;
+  if (esp_wifi_get_channel(&current, &secondary) == ESP_OK
+      && !espNowChannelRestoreRequired(current, target)) {
+    return ESP_OK;
+  }
   // Fail closed instead of silently moving to the build default. A failure can
   // be transient (scan/connect in progress), and changing the cached boot
   // channel here would split this node from peers which still use the selected
   // channel. Callers retry through their normal reconnect/tick paths.
-  return esp_wifi_set_channel(
-      activeEspNowChannel(), WIFI_SECOND_CHAN_NONE);
+  return esp_wifi_set_channel(target, WIFI_SECOND_CHAN_NONE);
 }
 
 } // namespace wifi

src/helpers/esp32/WiFiStationPolicy.h

@@ -76,13 +76,10 @@ inline wl_status_t beginStation(const char* ssid, const char* password) {
 // follow their existing disconnected/retry path.
 inline bool enforceStationChannel() {
   if (!kPrimaryEspNowRadio) return true;
-  if (WiFi.status() != WL_CONNECTED) {
-    // A disconnect and scan/association completion are asynchronous. Keep
-    // reasserting the boot channel so a first ESP_ERR_WIFI_STATE cannot leave
-    // the mesh parked on the router's former channel.
-    restoreEspNowChannel();
-    return true;
-  }
+  // beginStation(), disconnect handling, and setup-AP startup already restore
+  // the selected channel. Avoid polling the driver and attempting a channel
+  // write from every WebConfig and Companion loop while it is disconnected.
+  if (WiFi.status() != WL_CONNECTED) return true;
   if (WiFi.channel() == activeEspNowChannel()) return true;
   WiFi.disconnect(false, false);
   restoreEspNowChannel();