FIX(app): fix Kustomize path issue

- Remove ../../vault path from base kustomization (security)
- Reference vault/mas-postgres.yaml directly from prod overlay

deploy/k8s/overlays/prod/kustomization.yaml

@@ -9,6 +9,7 @@ resources:
   - resourcequota.yaml
   - externalsecret.yaml
   - serviceaccount.yaml
+  - ../../../vault/mas-postgres.yaml
 
 commonLabels:
   environment: production
@@ -16,5 +17,5 @@ commonLabels:
 # 이미지 태그 설정 (ArgoCD Image Updater가 자동으로 업데이트)
 images:
   - name: gitea0213.kro.kr/bluemayne/mas
-    newTag: main-sha-f338a6af2a274db31196d95702a0a319a7938728
+    newTag: main-sha-16e2dc2153719146680c0f8519e8350a31f2c843