test: usa setDb(memdb) para configurar DB en gating

Co-authored-by: aider (openrouter/openai/gpt-5) <aider@aider.chat>

tests/unit/services/group-sync.scheduler.gating.test.ts

@@ -2,6 +2,7 @@ import { describe, it, expect, beforeEach, afterEach } from 'bun:test';
 import { makeMemDb } from '../../helpers/db';
 import { GroupSyncService } from '../../../src/services/group-sync';
 import { AllowedGroups } from '../../../src/services/allowed-groups';
+import { setDb } from '../../../src/db/locator';
 
 describe('GroupSyncService - gating en scheduler de miembros (enforce)', () => {
   const envBackup = process.env;
@@ -11,8 +12,7 @@ describe('GroupSyncService - gating en scheduler de miembros (enforce)', () => {
     process.env = { ...envBackup, NODE_ENV: 'ci', GROUP_GATING_MODE: 'enforce' };
 
     const memdb = makeMemDb();
-    (GroupSyncService as any).dbInstance = memdb;
+    setDb(memdb);
-    (AllowedGroups as any).dbInstance = memdb;
 
     // Preparar caché de grupos activos (2 grupos: uno allowed y otro no)
     GroupSyncService.activeGroupsCache.clear();