feat(vela): retire mocked.turn.trigger from shared contract

apps/vela-gateway/src/index.js

@@ -206,6 +206,14 @@ function validateClientMessage(message) {
 		return 'message must match the shared envelope shape';
 	}
 
+	if (message.type === 'mocked.turn.trigger') {
+		if (!message.payload || typeof message.payload !== 'object' || Array.isArray(message.payload)) {
+			return 'message payload must be an object';
+		}
+
+		return null;
+	}
+
 	if (!isClientEventType(message.type)) {
 		return `unsupported client event type: ${message.type}`;
 	}

apps/vela-gateway/test/websocket-session.test.js

@@ -256,6 +256,15 @@ test('http routes stay available and preserve the root response contract', async
 	}
 });
 
+test('shared protocol only exposes currently supported client event types', () => {
+	assert.deepEqual(CLIENT_EVENT_TYPES, [
+		'session.start',
+		'input_audio.append',
+		'input_audio.commit',
+		'response.cancel'
+	]);
+});
+
 test('websocket connect creates and cleans up an ephemeral session', async () => {
 	const server = await startServer();