messages: pure builders for every event the bridge sends

src/messages builds Response, StateReport, DeferredResponse, ErrorResponse, ChangeReport and the scene, doorbell
and simple events from plain values; messageId and times are parameters, so a test compares whole objects.
StateBuilder collects properties checked by the descriptors, AlexaError and AlexaErrors carry the payload fields
of an error type. AlexaStatusMessage and AlexaErrorResponse move to src/compat and are written on the builders.
On the wire, against 1.5.2: a DeferredResponse has no context key, a ChangeReport has no correlationToken, the
namespace of an ErrorResponse follows its type, and a ChangeReport without a changed property is not published:
send() resolves "" and the bridge reports an error that names the endpoint.
143 tests pass (108 before).

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

dist/esm/compat/AlexaStatusMessage.d.ts

@@ -0,0 +1,61 @@
+import type { MqttClient } from "mqtt";
+import type { ChangeCause, Property } from "../messages/types.js";
+import { TemperatureSensorScale } from "./enums.js";
+import type { EndpointHealth, PowerController } from "./enums.js";
+/**
+ * A Response, StateReport, DeferredResponse or ChangeReport as 1.x builds it: device.getStatusMessage() or
+ * device.getChangeReport(), the add...Prop() calls, send(). The values are not checked.
+ */
+export declare class AlexaStatusMessage {
+    private readonly correlationToken;
+    private readonly rootTopic;
+    private readonly endpointId;
+    private readonly mqttClient;
+    private readonly isResponse;
+    private readonly isDeferred;
+    private readonly changeCause;
+    private readonly state;
+    private readonly messageId;
+    private estimatedDeferralInSeconds?;
+    /** Where a failed publish is reported (set by the Device that built this message, 1.5.2): send() never rejects. */
+    onPublishError?: (err: Error) => void;
+    constructor(correlationToken: string, rootTopic: string, endpointId: string, mqttClient: MqttClient, isResponse?: boolean, isDeferred?: boolean, changeCause?: ChangeCause | null);
+    private addProperty;
+    /** ChangeReport: the add*Prop calls that follow describe what CHANGED (the default for a change report). */
+    changed(): this;
+    /** ChangeReport: the add*Prop calls that follow describe the other, unchanged properties (context). */
+    unchanged(): this;
+    /** True for a ChangeReport (Device.getChangeReport). */
+    isChangeReport(): boolean;
+    /**
+     * The message as it will be published (for tests and logging). A DeferredResponse has no context. Throws
+     * MessageError for a ChangeReport without a changed property.
+     */
+    toJSON(): {
+        event: any;
+        context?: {
+            properties: Property[];
+        };
+    };
+    addModeControllerProp(instance: string, value: string, uncertaintyInMs?: number): this;
+    addThermostatModeProp(mode: string, uncertaintyInMs?: number): this;
+    addEstimatedDeferralTime(seconds: number): this;
+    addThermostatControllerProp(name: "lowerSetpoint" | "upperSetpoint" | "targetSetpoint", scale: TemperatureSensorScale, value: number, uncertaintyInMs?: number): this;
+    /** Alexa.EndpointHealth connectivity: EndpointHealth.OK / UNREACHABLE (the plain strings "OK" / "UNREACHABLE" are accepted too). */
+    addHealthProp(health: EndpointHealth | `${EndpointHealth}`, uncertaintyInMs?: number): this;
+    addPowerControllerProp(power: PowerController, uncertaintyInMs?: number): this;
+    addTemperatureSensorProp(scale: TemperatureSensorScale, value: number, uncertaintyInMs?: number): this;
+    addBrightnessControllerProp(brightness: number, uncertaintyInMs?: number): this;
+    addColorTemperatureControllerProp(colorTemp: number, uncertaintyInMs?: number): this;
+    addToggleControllerProp(state: PowerController, instance: string, uncertaintyInMs?: number): this;
+    /** A property built by the caller. It goes to the context, also in a ChangeReport after changed(). */
+    addContextProp(prop: Property): this;
+    /**
+     * Publish: a Response/StateReport to <root>/<endpoint>/alexaResponce (sendAsync: deferredResponse), a ChangeReport
+     * to <root>/changeReport (Alex2MQTT adds the user's token and posts it to the Alexa event gateway). Resolves with
+     * the topic, or "" when nothing was published: the publish failed, or the message is a ChangeReport without a
+     * changed property, which Alex2MQTT would drop. The error then goes to the bridge's "error" event (when listened
+     * to). Never rejects (1.5.1 did, so an un-caught send() could kill the host).
+     */
+    send(sendAsync?: boolean): Promise<string>;
+}