fix(api): import AuthModule in FederationModule for DI resolution

AuthGuard used across federation controllers depends on AuthService,
which requires AuthModule to be imported. Matches pattern used by
TasksModule, ProjectsModule, and CredentialsModule.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/federation/federation.module.ts

@@ -23,6 +23,7 @@ import { QueryService } from "./query.service";
 import { FederationAgentService } from "./federation-agent.service";
 import { validateFederationConfig } from "./federation.config";
 import { PrismaModule } from "../prisma/prisma.module";
+import { AuthModule } from "../auth/auth.module";
 import { TasksModule } from "../tasks/tasks.module";
 import { EventsModule } from "../events/events.module";
 import { ProjectsModule } from "../projects/projects.module";
@@ -32,6 +33,7 @@ import { RedisProvider } from "../common/providers/redis.provider";
   imports: [
     ConfigModule,
     PrismaModule,
+    AuthModule,
     TasksModule,
     EventsModule,
     ProjectsModule,