refactor sqlite queue

internal/email/queue.go

@@ -163,6 +163,6 @@ func (q *Queue) Stop() {
 	q.stop = true
 	// Wait for all emails to be processed
 	q.wg.Wait()
-	// Close the email queue
+	// Stop the email queue
 	close(q.emailQueue)
 }

internal/email/queue_test.go

@@ -22,7 +22,7 @@ func TestEmailQueue(t *testing.T) {
 		}
 		queue.AddEmail(email)
 	}
-	// Close the queue after all emails are processed
+	// Stop the queue after all emails are processed
 	queue.Stop()
 
 	assert.Equal(t, queue.FailedSendCount, 0)