discovery: generate capability JSON from the registry

A capability is a descriptor plus what the endpoint declares (device/Capability.ts), and its discovery object is
generated from the two. The new API is bridge.addDevice({ endpointId, name, categories, ... }) and
device.add(PowerController, options): both throw a DeclarationError that names the endpoint, the interface and
the instance (device/validate.ts), and leave the bridge and the device as they were. AlexaInterface is the same
Capability with the 1.x methods on it; it, ActionMapping and the enums moved to src/compat/, Device to src/device/.

What a 1.x caller can observe:
- every endpoint ends with { type: "AlexaInterface", interface: "Alexa", version: "3" } (alexa-interface.html);
  new Alex2MQTT(..., { alexaInterface: false }) leaves it out
- the fields of a capability object come in the order of Amazon's examples; their content is unchanged
- addCapability() with a name that is not an interface throws (1.5.2 announced it with the version "UNKNOWN")
- ActionMapping takes the payload as an object; a JSON string is parsed (1.5.2 sent the string), any other throws
- what Alexa would reject in a 1.x declaration is not refused: device.check() lists it and the bridge logs each
  line once, as "warning: ..." through the log hook, when it answers a discovery
- a device whose JSON cannot be built is left out of the answer and reported as an error event
- PowerController and EndpointHealth are the descriptors and keep ON/OFF and OK/UNREACHABLE; PowerState is new

Tests: six zoo devices declared the 1.x way give the JSON that Alexa accepted from 1.5.2 on 2026-09-28, plus the
Alexa capability. npm test: 85 pass (was 57) in 10-12 s, also on Node 18.20.8 and 20.20.2.

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

dist/esm/registry/interfaces/stubs.js

@@ -77,6 +77,20 @@ const TABLE = [
     ["Alexa.VideoRecorder", "1", [], "alexa-videorecorder.html"],
     ["Alexa.WakeOnLANController", "1", [], "alexa-wakeonlancontroller.html"],
 ];
+// What 1.5.2 added to the capability object of three of them
+const EXTRAS = {
+    // No properties object; supportsDeactivation and proactivelyReported on the capability itself
+    "Alexa.SceneController": ({ proactivelyReported }) => ({
+        properties: false,
+        topLevel: { supportsDeactivation: true, proactivelyReported },
+    }),
+    "Alexa.ThermostatController": () => ({
+        configuration: { supportedModes: ["HEAT", "COOL", "AUTO", "OFF"], supportsScheduling: false },
+    }),
+    "Alexa.ModeController": ({ options }) => (options.supportedModes?.length > 0
+        ? { configuration: { ordered: true, supportedModes: options.supportedModes } }
+        : {}),
+};
 function kindOf(namespace) {
     if (namespace.endsWith("Sensor"))
         return "sensor";
@@ -94,6 +108,7 @@ function stub([namespace, version, properties, page]) {
         instanced: false,
         properties: Object.fromEntries(properties.map((name) => [name, { name, value: s.unknown() }])),
         directives: {},
+        discovery: EXTRAS[namespace],
     };
 }
 export const STUBS = TABLE.map(stub);