fix(cluster): drive k8s cluster type from shared state

Replace unreliable Form.useWatch on the unregistered gpuInstanceOptions
path with explicit shared clusterType state. Fixes the type selector
being unclickable and flickering, and ensures a model cluster no longer
submits a stale gpuInstanceOptions payload.

src/pages/cluster-management/config/form-context.ts

@@ -5,6 +5,12 @@ import { ClusterListItem } from './types';
 interface FormContextProps {
   currentData?: ClusterListItem;
   submitAttempted?: boolean;
+  // K8s cluster type. `gpuInstanceOptions` on the form is derived from this —
+  // the selector, the static-address field, and submit all read this single
+  // source of truth instead of independently watching the (unregistered) form
+  // path, which did not re-render reliably.
+  clusterType?: 'model' | 'gpu';
+  setClusterType?: (type: 'model' | 'gpu') => void;
 }
 
 export const FormContext = createContext<FormContextProps>({});