fix(coord): add neutral interaction route alias

apps/gateway/src/coord/interaction-coordination.controller.test.ts

@@ -1,9 +1,20 @@
+const PATH_METADATA = 'path';
 import { describe, expect, it, vi } from 'vitest';
 import { InteractionCoordinationController } from './interaction-coordination.controller.js';
 
 const user = { id: 'operator-1', tenantId: 'tenant-a' };
 
 describe('InteractionCoordinationController', () => {
+  it('exposes the neutral canonical route and Mos compatibility alias over identical handlers', () => {
+    expect(Reflect.getMetadata(PATH_METADATA, InteractionCoordinationController)).toEqual([
+      'api/coord/interaction',
+      'api/coord/mos',
+    ]);
+    expect(InteractionCoordinationController.prototype.handoff).toBeTypeOf('function');
+    expect(InteractionCoordinationController.prototype.observe).toBeTypeOf('function');
+    expect(InteractionCoordinationController.prototype.result).toBeTypeOf('function');
+  });
+
   it('derives actor and tenant from the authenticated user rather than handoff input', async () => {
     const coordination = {
       handoff: vi.fn(async () => ({ handoffId: 'handoff-1' })),

apps/gateway/src/coord/interaction-coordination.controller.ts

@@ -22,7 +22,8 @@ import type {
 import { InteractionCoordinationService } from './interaction-coordination.service.js';
 
 /** Authenticated interaction-plane boundary for the handoff/observe/result-only interaction coordination contract. */
-@Controller('api/coord/mos')
+/** `api/coord/interaction` is canonical; the Mos path remains a compatibility alias. */
+@Controller(['api/coord/interaction', 'api/coord/mos'])
 @UseGuards(AuthGuard)
 export class InteractionCoordinationController {
   constructor(