fix(notification): ensure BuildNotificationList returns an empty slice instead of nil

internal/builders/notification_builder.go

@@ -25,9 +25,6 @@ func BuildNotification(item *models.Notification) *response.NotificationResponse
 }
 
 func BuildNotificationList(list []models.Notification) []response.NotificationResponse {
-	if len(list) == 0 {
-		return nil
-	}
 	results := make([]response.NotificationResponse, 0, len(list))
 	for i := range list {
 		if item := BuildNotification(&list[i]); item != nil {

internal/builders/notification_builder_test.go

@@ -0,0 +1,18 @@
+package builders
+
+import (
+	"testing"
+
+	"cs-agent/internal/models"
+)
+
+func TestBuildNotificationListReturnsEmptySlice(t *testing.T) {
+	results := BuildNotificationList([]models.Notification{})
+
+	if results == nil {
+		t.Fatalf("expected empty slice, got nil")
+	}
+	if len(results) != 0 {
+		t.Fatalf("expected empty slice, got %d items", len(results))
+	}
+}