feat(#709): add configured Discord interaction binding

apps/gateway/src/plugin/discord-ingress.security.spec.ts

@@ -3,6 +3,7 @@ import {
   createDiscordIngressEnvelope,
   verifyDiscordIngressEnvelope,
   type DiscordIngressPayload,
+  resolveDiscordInteractionBinding,
 } from '@mosaicstack/discord-plugin';
 import { validateDiscordServiceToken } from '../chat/chat.gateway-auth.js';
 import { DiscordReplayProtector } from './discord-replay-protector.js';
@@ -23,6 +24,25 @@ function createPayload(overrides: Partial<DiscordIngressPayload> = {}): DiscordI
 }
 
 describe('Discord ingress security', () => {
+  it('binds a differently named configured interaction instance without code changes', () => {
+    const binding = resolveDiscordInteractionBinding(
+      [
+        {
+          instanceId: 'Nova',
+          guildId: 'guild-001',
+          channelId: 'channel-001',
+          pairedUsers: { 'user-001': 'operator' },
+        },
+      ],
+      'guild-001',
+      'channel-001',
+      'user-001',
+      'send',
+    );
+
+    expect(binding?.instanceId).toBe('Nova');
+  });
+
   it('accepts only the configured Discord service identity', () => {
     expect(validateDiscordServiceToken(SERVICE_TOKEN, SERVICE_TOKEN)).toBe(true);
     expect(validateDiscordServiceToken('wrong-service-token', SERVICE_TOKEN)).toBe(false);