feat: add K8s deployment manifest with GW_URL and BLAZOR_ENVIRONMENT

- Create k8s/staging/backoffice-deployment.yaml with env vars:
  GW_URL=https://cms.se.kbs1.ir (injected into appsettings at startup)
  BLAZOR_ENVIRONMENT=Staging
- Update CI/CD to apply K8s manifests on deploy (like CMS does)
- This makes configuration persistent across CI/CD deployments

k8s/staging/backoffice-deployment.yaml

@@ -0,0 +1,84 @@
+---
+# BackOffice UI Deployment (Blazor WASM + nginx)
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: backoffice
+  namespace: default
+  labels:
+    app: backoffice
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: backoffice
+  template:
+    metadata:
+      labels:
+        app: backoffice
+    spec:
+      containers:
+      - name: backoffice
+        image: 194.5.195.53:30080/admin/backoffice:latest
+        imagePullPolicy: Always
+        ports:
+        - containerPort: 80
+          name: http
+        env:
+        - name: BLAZOR_ENVIRONMENT
+          value: "Staging"
+        - name: GW_URL
+          value: "https://cms.se.kbs1.ir"
+        resources:
+          requests:
+            memory: "128Mi"
+            cpu: "100m"
+          limits:
+            memory: "512Mi"
+            cpu: "500m"
+      imagePullSecrets:
+      - name: gitea-registry-secret
+
+---
+# BackOffice UI Service
+apiVersion: v1
+kind: Service
+metadata:
+  name: backoffice-svc
+  namespace: default
+spec:
+  selector:
+    app: backoffice
+  ports:
+  - port: 80
+    targetPort: 80
+  type: ClusterIP
+
+---
+# BackOffice UI Ingress
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: backoffice-ingress
+  namespace: default
+  annotations:
+    cert-manager.io/cluster-issuer: "letsencrypt-prod"
+    nginx.ingress.kubernetes.io/ssl-redirect: "true"
+    nginx.ingress.kubernetes.io/service-upstream: "true"
+spec:
+  ingressClassName: nginx
+  tls:
+  - hosts:
+    - backoffice.se.kbs1.ir
+    secretName: backoffice-tls
+  rules:
+  - host: backoffice.se.kbs1.ir
+    http:
+      paths:
+      - path: /
+        pathType: Prefix
+        backend:
+          service:
+            name: backoffice-svc
+            port:
+              number: 80