examples: one runnable file per recipe on the 2.0 API, the 1.x files in examples/legacy

Ten recipes: lamp, colour lamp, thermostat, blind, lock (deferred), contact
sensor (ChangeReport), scene, doorbell (raise), typed errors, and a plug as an
ES module. Each reads ALEX2MQTT_USERNAME, _PASSWORD and _ROOT_TOPIC and names
the ones that are missing. The nine examples of 1.5.2 move to examples/legacy
unchanged.

test/examples.test.js starts every file with node, its broker connection sent
to a broker on 127.0.0.1 (test/helpers/loopback.js), discovers the device,
sends directives and checks the answers. A legacy file is started and its
discovery compared with the answer the 1.5.2 build gave, recorded in
test/fixtures/legacy-examples.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

examples/legacy/ExampleModeController.js

@@ -0,0 +1,120 @@
+// Import the library ("alex2node" is the installed package; inside this checkout it resolves to the built dist/ via package.json "exports")
+const {
+  Alex2MQTT,
+  AlexaInterfaceType,
+  PowerController,
+  DisplayCategory,
+  EndpointHealth,
+} = require("alex2node");
+
+require("dotenv").config(); // Load environment variables from .env file
+
+// Simulated in-memory device state (used for example/demo purposes)
+let currentMode = "mode.fanmode.Normal";
+
+// Load MQTT connection credentials and root topic from environment variables
+const username = process.env.MQTT_USERNAME;
+const password = process.env.MQTT_PASSWORD;
+const rootTopic = process.env.MQTT_ROOT_TOPIC;
+
+// Create and initialize a new Alexa-to-MQTT client
+const alex2NodeClient = new Alex2MQTT(username, password, rootTopic, false);
+alex2NodeClient.connect(); // Connect to the MQTT broker
+alex2NodeClient.on("error", (e) => console.error("broker:", e.message)); // Log broker errors (on 1.5.0 this listener is also what keeps an outage from killing the process)
+
+// Define the device name (Test mode controller)
+const deviceName = "Test mode controller";
+
+// Register the device with a unique endpoint ID (unique per root topic, e.g. "fan-1")
+const modeControllerDevice = alex2NodeClient.registerDevice(
+  deviceName,
+  "fan-1",
+  [DisplayCategory.OTHER]
+);
+
+// Add the 'MODE_CONTROLLER' capability for controlling device modes
+const modeController = modeControllerDevice.addCapability(
+  AlexaInterfaceType.MODE_CONTROLLER
+);
+
+modeController.setInstance("mode.fanmode");
+modeController.addFriendlyName("Fan Mode", "en-US");
+modeController.addSupportedModes([
+  {
+    value: "mode.fanmode.Normal",
+    modeResources: {
+      friendlyNames: [
+        {
+          "@type": "text",
+          value: {
+            text: "Normal",
+            locale: "en-US",
+          },
+        },
+      ],
+    },
+  },
+  {
+    value: "mode.fanmode.Low",
+    modeResources: {
+      friendlyNames: [
+        {
+          "@type": "text",
+          value: {
+            text: "Low",
+            locale: "en-US",
+          },
+        },
+      ],
+    },
+  },
+]);
+
+// Log the device name to verify registration
+console.log(modeControllerDevice.getName());
+
+/**
+ * Handle Alexa's ReportState directive.
+ * This occurs when Alexa queries the current state of the device (e.g., during routines or device status checks).
+ */
+modeControllerDevice.on("ReportState", (payload) => {
+  console.log("ReportState received!", payload);
+
+  const { correlationToken } = payload.header;
+
+  const status = modeControllerDevice.getStatusMessage(correlationToken);
+
+  status
+    .addHealthProp(EndpointHealth.OK) // Device is healthy
+    .addModeControllerProp("mode.fanmode", currentMode);
+
+  status.send(); // Send the state report back to Alexa
+});
+
+/**
+ * Handle incoming control directives (e.g., SetMode).
+ * These directives come from Alexa when a user issues a command.
+ */
+modeControllerDevice.on("Event", (directive, interfaceType) => {
+  console.log("Event received", { directive, interfaceType });
+  // Ensure the interfaceType is either PowerController or other valid interfaces
+  if (interfaceType === AlexaInterfaceType.MODE_CONTROLLER) {
+    const name = directive.header.name;
+    const token = directive.header.correlationToken;
+    const instance = directive.header.instance;
+
+    if (instance == "mode.fanmode") {
+      if (name === "SetMode") {
+        currentMode = directive.payload.mode;
+      }
+    }
+
+    const status = modeControllerDevice.getStatusMessage(token, true);
+
+    status
+      .addHealthProp(EndpointHealth.OK) // Device is healthy
+      .addModeControllerProp("mode.fanmode", currentMode);
+
+    status.send(); // Send the state report back to Alexa
+  }
+});