changed poll and some UI bugs.

frontend/src/App.jsx

@@ -36,7 +36,6 @@ export default function App() {
   const [loading, setLoading] = useState(true);
 
   async function refresh() {
-    setError('');
     try {
       const [healthResult, vmsResult, jobsResult, schedulesResult, nodesResult] = await Promise.allSettled([
         api.get('/health'),
@@ -47,20 +46,20 @@ export default function App() {
       ]);
 
       if (healthResult.status === 'fulfilled') {
-        setHealth(healthResult.value.data);
+        setStableState(setHealth, healthResult.value.data);
       } else {
-        setHealth(healthResult.reason.response?.data || { ok: false, checks: {} });
+        setStableState(setHealth, healthResult.reason.response?.data || { ok: false, checks: {} });
       }
 
-      if (vmsResult.status === 'fulfilled') setVms(vmsResult.value.data);
-      if (jobsResult.status === 'fulfilled') setJobs(jobsResult.value.data);
-      if (schedulesResult.status === 'fulfilled') setSchedules(schedulesResult.value.data);
-      if (nodesResult.status === 'fulfilled') setNodes(nodesResult.value.data);
+      if (vmsResult.status === 'fulfilled') setStableState(setVms, vmsResult.value.data);
+      if (jobsResult.status === 'fulfilled') setStableState(setJobs, jobsResult.value.data);
+      if (schedulesResult.status === 'fulfilled') setStableState(setSchedules, schedulesResult.value.data);
+      if (nodesResult.status === 'fulfilled') setStableState(setNodes, nodesResult.value.data);
 
       const firstFailure = [healthResult, vmsResult, jobsResult, schedulesResult, nodesResult].find((result) => result.status === 'rejected');
-      if (firstFailure) setError(errorMessage(firstFailure.reason));
+      setStableState(setError, firstFailure ? errorMessage(firstFailure.reason) : '');
     } catch (requestError) {
-      setError(errorMessage(requestError));
+      setStableState(setError, errorMessage(requestError));
     } finally {
       setLoading(false);
     }
@@ -227,6 +226,16 @@ export default function App() {
   }
 }
 
+function setStableState(setter, nextValue) {
+  setter((currentValue) => (
+    stableStringify(currentValue) === stableStringify(nextValue) ? currentValue : nextValue
+  ));
+}
+
+function stableStringify(value) {
+  return JSON.stringify(value);
+}
+
 function NavButton({ active, icon: Icon, label, onClick }) {
   return (
     <button

frontend/src/components/Nodes.jsx

@@ -4,6 +4,7 @@ import { api, errorMessage } from '../api.js';
 
 export function Nodes({ nodes, onChanged }) {
   const [drafts, setDrafts] = useState(() => nodes);
+  const [dirtyIds, setDirtyIds] = useState(() => new Set());
   const [newNode, setNewNode] = useState({ name: '', baseUrl: '', token: '', enabled: true });
   const [message, setMessage] = useState('');
   const [error, setError] = useState('');
@@ -29,6 +30,7 @@ export function Nodes({ nodes, onChanged }) {
       const body = { ...node };
       if (!body.token) delete body.token;
       await api.put(`/nodes/${encodeURIComponent(node.id)}`, body);
+      setDirtyIds((current) => withoutId(current, node.id));
       setMessage('Node saved.');
       await onChanged();
     } catch (requestError) {
@@ -53,6 +55,7 @@ export function Nodes({ nodes, onChanged }) {
     setMessage('');
     try {
       await api.delete(`/nodes/${encodeURIComponent(node.id)}`);
+      setDirtyIds((current) => withoutId(current, node.id));
       setMessage('Node deleted.');
       await onChanged();
     } catch (requestError) {
@@ -61,12 +64,30 @@ export function Nodes({ nodes, onChanged }) {
   }
 
   function updateDraft(id, values) {
+    setDirtyIds((current) => withId(current, id));
     setDrafts((current) => current.map((node) => node.id === id ? { ...node, ...values } : node));
   }
 
+  async function toggleNodeEnabled(node, enabled) {
+    setError('');
+    setMessage('');
+    setDrafts((current) => current.map((draft) => draft.id === node.id ? { ...draft, enabled } : draft));
+    try {
+      await api.put(`/nodes/${encodeURIComponent(node.id)}`, { enabled });
+      setMessage(enabled ? 'Node enabled.' : 'Node disabled.');
+      await onChanged();
+    } catch (requestError) {
+      setError(errorMessage(requestError));
+      await onChanged();
+    }
+  }
+
   useEffect(() => {
-    setDrafts(nodes);
-  }, [nodes]);
+    setDrafts((current) => {
+      const currentById = new Map(current.map((node) => [node.id, node]));
+      return nodes.map((node) => dirtyIds.has(node.id) ? { ...node, ...currentById.get(node.id) } : node);
+    });
+  }, [dirtyIds, nodes]);
 
   return (
     <section className="space-y-5">
@@ -107,7 +128,7 @@ export function Nodes({ nodes, onChanged }) {
               {drafts.map((node) => (
                 <tr key={node.id}>
                   <td className="px-4 py-3">
-                    <input checked={node.enabled} className="h-4 w-4 accent-cyan-500" onChange={(event) => updateDraft(node.id, { enabled: event.target.checked })} type="checkbox" />
+                    <input checked={node.enabled} className="h-4 w-4 accent-cyan-500" onChange={(event) => toggleNodeEnabled(node, event.target.checked)} type="checkbox" />
                   </td>
                   <td className="px-4 py-3"><input className="h-9 w-full rounded-md border border-zinc-700 bg-zinc-950 px-2 text-zinc-100" onChange={(event) => updateDraft(node.id, { name: event.target.value })} value={node.name} /></td>
                   <td className="px-4 py-3"><input className="h-9 w-full rounded-md border border-zinc-700 bg-zinc-950 px-2 text-zinc-100" onChange={(event) => updateDraft(node.id, { baseUrl: event.target.value })} value={node.baseUrl} /></td>
@@ -131,6 +152,18 @@ export function Nodes({ nodes, onChanged }) {
   );
 }
 
+function withId(set, id) {
+  const next = new Set(set);
+  next.add(id);
+  return next;
+}
+
+function withoutId(set, id) {
+  const next = new Set(set);
+  next.delete(id);
+  return next;
+}
+
 function Input({ label, onChange, placeholder = '', type = 'text', value }) {
   return (
     <label className="block text-sm text-zinc-300">