fix(llm): default backend router to one replica

Signed-off-by: Mike Camp <mcamp@nvidia.com>

Author: mikeyrcamp

deploy/helm/llm-request-router/llm-request-router/values.yaml

@@ -70,7 +70,7 @@ llmRequestRouter:
   # than one.
   backendRouter:
     enabled: false
-    replicaCount: 2
+    replicaCount: 1
     image:
       registry: ""
       repository: ""

deploy/helm/llm-request-router/scripts/check-backend-router-render.sh

@@ -38,10 +38,25 @@ assert_contains() {
   fi
 }
 
+assert_backend_router_replicas() {
+  local expected="$1"
+  local actual
+  actual="$(awk '
+    $0 == "kind: Deployment" { in_deployment = 1; backend_router = 0 }
+    in_deployment && $1 == "name:" && $2 == "llm-request-router-backend-router" { backend_router = 1 }
+    backend_router && $1 == "replicas:" { print $2; exit }
+  ' "$rendered")"
+  if [[ "$actual" != "$expected" ]]; then
+    echo "FAIL: backend router must default to ${expected} replica; rendered ${actual:-none}" >&2
+    exit 1
+  fi
+}
+
 assert_contains "name: llm-request-router-backend-router" \
   "backend router workload and Service must use a stable name"
 assert_contains "kind: Deployment" \
   "backend router must render as a Deployment"
+assert_backend_router_replicas "1"
 assert_contains "kind: Role" \
   "backend router must render namespaced RBAC"
 assert_contains "resources: [\"endpointslices\"]" \