test: aislar DB en memoria para ResponseQueue (backoff)

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

tests/unit/services/response-queue.test.ts

@@ -108,6 +108,24 @@ describe('ResponseQueue (persistent add)', () => {
 });
 
 describe('ResponseQueue (retries/backoff)', () => {
+  beforeAll(() => {
+    // Re-crear DB en memoria y reinyectar para este bloque
+    testDb = new Database(':memory:');
+    initializeDatabase(testDb);
+    originalDbInstance = (ResponseQueue as any).dbInstance;
+    (ResponseQueue as any).dbInstance = testDb;
+  });
+
+  afterAll(() => {
+    (ResponseQueue as any).dbInstance = originalDbInstance;
+    testDb.close();
+  });
+
+  beforeEach(() => {
+    // Limpiar tabla entre tests
+    testDb.exec('DELETE FROM response_queue');
+  });
+
   function isoNow(): string {
     return new Date().toISOString().replace('T', ' ').replace('Z', '');
   }