Import ESP_UniClock (upstream 1189810)

Vendored from https://github.com/gpeter62/ESP_UniClock: the sketch
source, the web UI and the libraries the ESP8266 build needs, unpacked
from the bundled zips. Adds a PlatformIO project for the ESP-12. The
source is unchanged; local changes follow as separate commits.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

firmware/uniclock/lib/ESPAsyncWiFiManager/examples/OnDemandConfigPortal/OnDemandConfigPortal.ino

@@ -0,0 +1,67 @@
+#if defined(ESP8266)
+#include <ESP8266WiFi.h>          //https://github.com/esp8266/Arduino
+#else
+#include <WiFi.h>
+#endif
+
+//needed for library
+#include <ESPAsyncWebServer.h>
+#include <ESPAsyncWiFiManager.h>         //https://github.com/tzapu/WiFiManager
+
+
+AsyncWebServer server(80);
+DNSServer dns;
+
+// select wich pin will trigger the configuraton portal when set to LOW
+// ESP-01 users please note: the only pins available (0 and 2), are shared
+// with the bootloader, so always set them HIGH at power-up
+#define TRIGGER_PIN 0
+
+
+void setup() {
+  // put your setup code here, to run once:
+  Serial.begin(115200);
+  Serial.println("\n Starting");
+
+  pinMode(TRIGGER_PIN, INPUT);
+}
+
+
+void loop() {
+  // is configuration portal requested?
+  if ( digitalRead(TRIGGER_PIN) == LOW ) {
+    //WiFiManager
+    //Local intialization. Once its business is done, there is no need to keep it around
+    AsyncWiFiManager wifiManager(&server,&dns);
+
+    //reset settings - for testing
+    //wifiManager.resetSettings();
+
+    //sets timeout until configuration portal gets turned off
+    //useful to make it all retry or go to sleep
+    //in seconds
+    //wifiManager.setTimeout(120);
+
+    //it starts an access point with the specified name
+    //here  "AutoConnectAP"
+    //and goes into a blocking loop awaiting configuration
+
+    //WITHOUT THIS THE AP DOES NOT SEEM TO WORK PROPERLY WITH SDK 1.5 , update to at least 1.5.1
+    //WiFi.mode(WIFI_STA);
+
+    if (!wifiManager.startConfigPortal("OnDemandAP")) {
+      Serial.println("failed to connect and hit timeout");
+      delay(3000);
+      //reset and try again, or maybe put it to deep sleep
+      ESP.reset();
+      delay(5000);
+    }
+
+    //if you get here you have connected to the WiFi
+    Serial.println("connected...yeey :)");
+  }
+
+
+  // put your main code here, to run repeatedly:
+
+}