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/arduino-home-assistant-main/examples/nano33iot/nano33iot.ino

@@ -0,0 +1,53 @@
+#include <WiFiNINA.h>
+#include <ArduinoHA.h>
+
+#define LED_PIN         9
+#define BROKER_ADDR     IPAddress(192,168,0,17)
+#define WIFI_SSID       "MyNetwork"
+#define WIFI_PASSWORD   "MyPassword"
+
+WiFiClient client;
+HADevice device;
+HAMqtt mqtt(client, device);
+HASwitch led("led", false); // "led" is unique ID of the switch. You should define your own ID.
+
+void onSwitchStateChanged(bool state, HASwitch* s)
+{
+    digitalWrite(LED_PIN, (state ? HIGH : LOW));
+}
+
+void setup() {
+    Serial.begin(9600);
+    Serial.println("Starting...");
+
+    // Unique ID must be set!
+    byte mac[WL_MAC_ADDR_LENGTH];
+    WiFi.macAddress(mac);
+    device.setUniqueId(mac, sizeof(mac));
+
+    pinMode(LED_PIN, OUTPUT);
+    digitalWrite(LED_PIN, LOW);
+
+    // connect to wifi
+    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
+    while (WiFi.status() != WL_CONNECTED) {
+        Serial.print(".");
+        delay(500); // waiting for the connection
+    }
+    Serial.println();
+    Serial.println("Connected to the network");
+
+    // set device's details (optional)
+    device.setName("Nano 33 IoT");
+    device.setSoftwareVersion("1.0.0");
+
+    // handle switch state
+    led.onStateChanged(onSwitchStateChanged);
+    led.setName("My LED"); // optional
+
+    mqtt.begin(BROKER_ADDR);
+}
+
+void loop() {
+    mqtt.loop();
+}