fix: remove per-card Refresh button in InstanceCard, consolidate to page-level refresh

- Remove onRefresh prop from InstanceCard component
- Remove handleRefresh callback from InstancesManagementPage
- Remove onRefresh passing from both filtered and unfiltered instance lists
- Keep global page refresh button in PageHeader

frontend/src/features/artifact/instances/pages/InstancesManagementPage.tsx

@@ -188,37 +188,6 @@ const InstancesManagementPage: React.FC = () => {
     };
   }, [autoRefresh]);
 
-  const handleRefresh = useCallback(async (instance: Instance) => {
-    const clusterId = instance.clusterId;
-    if (!clusterId) {
-      toastError("Cluster ID is missing");
-      return;
-    }
-
-    toastInfo(`Refreshing status for "${instance.name || "instance"}"...`, {
-      title: "Instance Status",
-      durationMs: 1800,
-      mergeKey: `instance-refresh-${instance.id || clusterId}`,
-    });
-
-    try {
-      const normalized = await fetchClusterInstances(clusterId);
-      setInstancesByCluster((prev) => {
-        const next = new Map(prev);
-        next.set(clusterId, normalized.instances);
-        return next;
-      });
-      setInstanceTotals((prev) => {
-        const next = new Map(prev);
-        next.set(clusterId, normalized.total);
-        return next;
-      });
-      success(SuccessMessages.INSTANCE_STATUS_REFRESHED);
-    } catch (err: unknown) {
-      toastError(formatApiError(err) || InstanceErrors.STATUS_FETCH_FAILED);
-    }
-  }, [success, toastError, toastInfo]);
-
   const handleModify = useCallback((instance: Instance) => {
     setModifyInstance(instance);
   }, []);
@@ -459,7 +428,7 @@ const InstancesManagementPage: React.FC = () => {
                           instance={instance}
                           onModify={handleModify}
                           onTerminate={handleTerminate}
-                          onRefresh={handleRefresh}
+
                           onViewEntries={handleViewEntries}
                           onViewDiagnostics={handleViewDiagnostics}
                         />
@@ -476,7 +445,7 @@ const InstancesManagementPage: React.FC = () => {
                   instance={instance}
                   onModify={handleModify}
                   onTerminate={handleTerminate}
-                  onRefresh={handleRefresh}
+
                   onViewEntries={handleViewEntries}
                   onViewDiagnostics={handleViewDiagnostics}
                 />