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/messages/index.js

@@ -0,0 +1,5 @@
+// The messages of the bridge without the bridge: builders, the state collector and the errors.
+export { changeReport, deferredResponse, doorbellPress, errorResponse, response, sceneEvent, simpleEvent, stateReport, MessageError, } from "./build.js";
+export { AlexaError, AlexaErrors, errorNamespace } from "./errors.js";
+export { property } from "./property.js";
+export { StateBuilder } from "./StateBuilder.js";