test: usar setDb y resetDb para gestionar DB en tests

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

tests/unit/tasks/complete-reaction.test.ts

@@ -4,6 +4,7 @@ import { initializeDatabase } from '../../../src/db';
 import { TaskService } from '../../../src/tasks/service';
 import { ResponseQueue } from '../../../src/services/response-queue';
 import { AllowedGroups } from '../../../src/services/allowed-groups';
+import { setDb, resetDb } from '../../../src/db/locator';
 
 import { toIsoSql } from '../../helpers/dates';
 
@@ -15,14 +16,12 @@ describe('TaskService - reacción ✅ al completar (Fase 2)', () => {
     envBackup = { ...process.env };
     memdb = new Database(':memory:');
     initializeDatabase(memdb);
-    (TaskService as any).dbInstance = memdb;
-    (ResponseQueue as any).dbInstance = memdb;
-    (AllowedGroups as any).dbInstance = memdb;
+    setDb(memdb);
   });
 
   afterAll(() => {
     process.env = envBackup;
-    try { memdb.close(); } catch {}
+    try { resetDb(); memdb.close(); } catch {}
   });
 
   beforeEach(() => {