deploy(demo,prod): promote frontend to 1087

Sync demo and prod frontend image with the latest built in dev. Chart stays at
0.2.7 and the new admin service is intentionally not promoted (its app is not yet
merged / green), so no admin workload is deployed to demo or prod.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: manuelhummler

infrastructure/hopps/overlays/demo/helm-release.yaml

@@ -75,7 +75,7 @@ spec:
     # frontend
     frontend:
       image:
-        tag: "1083"
+        tag: "1087"
       envFrom:
         - secretRef:
             name: frontend

infrastructure/hopps/overlays/prod/helm-release.yaml

@@ -67,7 +67,7 @@ spec:
     # frontend
     frontend:
       image:
-        tag: "1083"
+        tag: "1087"
       envFrom:
         - secretRef:
             name: frontend