Make ESP32 OTA startup handle WiFi and WebConfig automatically

Report the upload address and required network, honor AP switches on an existing uploader, and keep delayed WebConfig cleanup from disabling OTA WiFi. Preserve actionable startup errors and account for OTA in wireless state controls.

Exercise the production OTA lifecycle and stock website console, including power-saving idle sessions, in host regression tests.

src/helpers/esp32/WebConfigServer.cpp

@@ -245,12 +245,11 @@ static_assert(WC_BOARD_CMD_COUNT <= 8, "board command mask must fit uint8_t");
 // POST so nothing in the sequence runs, rather than failing halfway with a
 // reply that does not explain itself. Returns the reason, or NULL if fine.
 static const char* wcCliUnavailable(const char* cmd, bool streamed = false) {
-  // ESP32Board::startOTAUpdate() does `new AsyncWebServer(80)` with no bind
-  // check and answers "Started" regardless. The portal already holds port 80,
-  // so from here it can only leak the allocation, inhibit sleep, and lie.
+  // OTA stops this portal, including the session carrying this command. It
+  // needs an independent reply route so the user receives the upload URL.
   if (strncmp(cmd, "start ota", 9) == 0) {
-    return "start ota needs port 80, which this portal is using. "
-           "Run it from the serial console, or use `ota update`.";
+    return "start ota stops WebConfig. Run it from USB/Bluetooth or LoRa "
+           "to receive the upload URL, or use `ota update`.";
   }
   // `clock sync` sets the clock from the CALLER's timestamp. Web requests carry
   // none (execCommand passes 0), so CommonCLI always rejects it as moving the
@@ -967,6 +966,31 @@ void WebConfigServer::requestStop() {
   _stop_warned = false;
 }
 
+bool WebConfigServer::stopForOTA(char reply[]) {
+  if (!isRunning() && !isStopping()) return true;
+  // Keep a STA interface alive while removing our setup AP. Switching the
+  // last interface off and immediately creating the OTA AP races ESP32 netif
+  // teardown. A connected station keeps its address throughout the handoff.
+  if (_was_setup_ap && !WiFi.enableSTA(true)) {
+    strcpy(reply, "ERR: could not prepare WiFi for OTA");
+    return false;
+  }
+  _keep_wifi_on_stop = true;
+  requestStop(); // Detaches routes and releases port 80 synchronously.
+  if (_was_setup_ap) {
+    WiFi.softAPdisconnect(true);
+    // Arduino 2.x can return false even when enableAP(false) succeeded.
+    // Check the resulting mode instead of that return value.
+    if (WiFi.getMode() & WIFI_AP) {
+      strcpy(reply, "ERR: WebConfig stopped; WiFi AP handoff failed");
+      return false;
+    }
+    _was_setup_ap = false;
+  }
+  strcpy(reply, "WebConfig stopped");
+  return true;
+}
+
 void WebConfigServer::finalizeTeardown() {
   closeTerminal();
   // Async requests keep a pointer to their server until disconnect. Retain the
@@ -976,7 +1000,7 @@ void WebConfigServer::finalizeTeardown() {
   delete _dns;
   _dns = NULL;
   const bool was_setup_ap = _was_setup_ap;
-  if (was_setup_ap) {
+  if (was_setup_ap && !_keep_wifi_on_stop) {
     WiFi.softAPdisconnect(true);
     // Nothing else owns WiFi when we raised the AP: either the node is
     // unconfigured, or `start webconfig ap` required the bridge stopped.
@@ -985,11 +1009,12 @@ void WebConfigServer::finalizeTeardown() {
     } else {
       WiFi.mode(WIFI_STA);
     }
-    _was_setup_ap = false;
   }
-  if (_owns_wifi && !was_setup_ap) {
+  if (_owns_wifi && !was_setup_ap && !_keep_wifi_on_stop) {
     stopOwnedWiFiRadio();
   }
+  _was_setup_ap = false;
+  _keep_wifi_on_stop = false;
   _initial_setup = false;
   _setup_started_at = 0;
   _stopping = false;