test: usar setDb y resetDb para configurar DB global en pruebas

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

tests/unit/tasks/service.gating.test.ts

@@ -3,6 +3,7 @@ import Database from 'bun:sqlite';
 import { initializeDatabase } from '../../../src/db';
 import { TaskService } from '../../../src/tasks/service';
 import { AllowedGroups } from '../../../src/services/allowed-groups';
+import { setDb, resetDb } from '../../../src/db/locator';
 import { toIsoSql } from '../../helpers/dates';
 
 function seedGroup(db: Database, groupId: string) {
@@ -65,12 +66,12 @@ describe('TaskService - gating en creación con group_id (enforce)', () => {
     process.env = { ...envBackup, NODE_ENV: 'test', GROUP_GATING_MODE: 'enforce' };
     memdb = new Database(':memory:');
     initializeDatabase(memdb);
-    (TaskService as any).dbInstance = memdb;
-    (AllowedGroups as any).dbInstance = memdb;
+    setDb(memdb);
   });
 
   afterEach(() => {
     process.env = envBackup;
+    resetDb();
     memdb.close();
   });