Add OC_JWT_SECRET for auth-service

Problem: Auth-service requires OC_JWT_SECRET to mint/validate JWT tokens.
Root cause: Only OC_TOKEN_MANAGER_JWT_SECRET was set, not OC_JWT_SECRET.

According to OpenCloud docs, auth-service needs:
- OC_JWT_SECRET or AUTH_SERVICE_JWT_SECRET

Changes:
- Added OC_JWT_SECRET environment variable
- Points to same jwt-secret as OC_TOKEN_MANAGER_JWT_SECRET

Why: Auth-service uses OC_JWT_SECRET to validate tokens from OIDC flow.
Without it, authentication fails silently.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/opencloud/opencloud-deployment.yaml

@@ -101,12 +101,17 @@ spec:
         - name: OPENCLOUD_CONFIG_DIR
           value: "/etc/opencloud"
 
-        # Core secrets (token manager)
+        # Core secrets (token manager and auth-service JWT)
         - name: OC_TOKEN_MANAGER_JWT_SECRET
           valueFrom:
             secretKeyRef:
               name: opencloud-jwt-secret
               key: jwt-secret
+        - name: OC_JWT_SECRET
+          valueFrom:
+            secretKeyRef:
+              name: opencloud-jwt-secret
+              key: jwt-secret
         - name: OC_MACHINE_AUTH_API_KEY
           valueFrom:
             secretKeyRef: