Fix loading and some tests

internal/config/parse_test.go

@@ -31,10 +31,10 @@ kind: ClusterConfiguration
 metadata:
   name: test-cluster
 spec:
-  clusterCIDR: "10.0.0.0/16"
-  serviceCIDR: "10.1.0.0/16"
-  nodeSubnetBits: 8 # /24 for nodes
-  apiPort: 8080 # Non-default
+  cluster_cidr: "10.0.0.0/16"
+  service_cidr: "10.1.0.0/16"
+  node_subnet_bits: 8 # /24 for nodes
+  api_port: 8080 # Non-default
 `
 	filePath := createTestClusterKatFile(t, yamlContent)
 
@@ -97,7 +97,7 @@ spec:
   clusterCIDR: "10.0.0.0/16"
   serviceCIDR: "10.1.0.0/16"
 `,
-			wantErr: "metadata.name is required",
+			wantErr: "metadata section not found",
 		},
 		{
 			name: "missing clusterCIDR",