Fix CI/CD job dependencies and YAML syntax

- Make deploy job dependency optional in ghost-upload jobs
- Change preview job to depend on staging instead of deploy
- Ensures pipeline works on feature branches without deploy job

.gitlab-ci.yml

@@ -39,7 +39,7 @@ preview:
     - echo "Deploying branch preview..."
     - echo "Preview available at preview URL"
   needs:
-    - deploy
+    - staging
   artifacts:
     paths:
       - public