feat(protocol): add shared WebSocket contract package

apps/vela-gateway/src/index.js

@@ -1,4 +1,9 @@
 const Fastify = require('fastify');
+const {
+	CLIENT_EVENT_TYPES,
+	PROTOCOL_PACKAGE_NAME,
+	SERVER_EVENT_TYPES
+} = require('@vela/protocol');
 
 function buildServer() {
 	const app = Fastify({ logger: true });
@@ -7,7 +12,12 @@ function buildServer() {
 		service: 'vela-gateway',
 		status: 'ok',
 		transport: 'http',
-		next: 'websocket session skeleton'
+		next: 'websocket session skeleton',
+		protocol: {
+			package: PROTOCOL_PACKAGE_NAME,
+			clientEventCount: CLIENT_EVENT_TYPES.length,
+			serverEventCount: SERVER_EVENT_TYPES.length
+		}
 	}));
 
 	app.get('/health', async () => ({ status: 'ok' }));