swarm-ui: show agent panel read failures as text and keep loaded data

Inference, resource caps and linked accounts showed a failed read as a
badge with the reason in a hover title, which keyboard and touch users
cannot read. They now use ApiErrorPanel, and a list that already loaded
stays on screen under a failed refetch.

docs/swarm/ui.md

@@ -435,7 +435,10 @@ name that already holds an account; delete that account first to replace it.
 The agent's detail panel lists its linked accounts under **accounts**, one row
 per account: kind, name and host. Opening an agent makes one request,
 `GET /api/hives/{hive}/agents/{agent}/linked-accounts`, which returns every
-account of that agent as names and hosts and never a credential.
+account of that agent as names and hosts and never a credential. When the panel
+fails to read the accounts, the inference settings or the resource caps, it
+shows the reason as text. A list the panel already loaded stays on screen
+beneath the error.
 
 | kind    | one row per                                 | name        | host                     |
 | ------- | ------------------------------------------- | ----------- | ------------------------ |

frontend/packages/swarm-ui/src/agent/detail/AgentInference.tsx

@@ -205,21 +205,23 @@ export function AgentInference({ agent }: { agent: string }) {
     };
   }, [agent, reload]);
 
-  if (error) {
-    return (
-      <Badge
-        tone="negative"
-        value="inference unavailable"
-        title={error.detail ?? "reading the inference settings failed"}
-      />
-    );
+  // Shown as text, not a hover title. Settings already loaded stay under a
+  // failed refetch, so a save that worked is not hidden by a read that did not.
+  const errorPanel = error ? (
+    <ApiErrorPanel
+      context="reading the inference settings failed"
+      problem={error}
+    />
+  ) : null;
+  if (view === null) {
+    return errorPanel ?? <span class="ui-agent-inference-muted">…</span>;
   }
-  if (view === null) return <span class="ui-agent-inference-muted">…</span>;
 
   const { configured, effective } = view;
   const swarmModels = configured?.subagent_models ?? [];
   return (
     <div class="ui-agent-inference">
+      {errorPanel}
       <ul class="ui-agent-inference-list">
         <li>
           {effective ? (

frontend/packages/swarm-ui/src/agent/detail/AgentLimits.tsx

@@ -114,19 +114,18 @@ export function AgentLimits({ agent }: { agent: string }) {
     };
   }, [agent, reload]);
 
-  if (error) {
-    return (
-      <Badge
-        tone="negative"
-        value="resource caps unavailable"
-        title={error.detail ?? "reading the resource caps failed"}
-      />
-    );
+  // Shown as text, not a hover title. Caps already loaded stay under a
+  // failed refetch, so a save that worked is not hidden by a read that did not.
+  const errorPanel = error ? (
+    <ApiErrorPanel context="reading the resource caps failed" problem={error} />
+  ) : null;
+  if (caps === null) {
+    return errorPanel ?? <span class="ui-agent-limits-muted">…</span>;
   }
-  if (caps === null) return <span class="ui-agent-limits-muted">…</span>;
 
   return (
     <div class="ui-agent-limits">
+      {errorPanel}
       <ul class="ui-agent-limits-list">
         <li>
           <Badge label="cpu quota" value={caps.cpu_quota ?? HIVE_DECIDES} />

frontend/packages/swarm-ui/src/agent/detail/LinkedAccounts.tsx

@@ -156,21 +156,26 @@ export function LinkedAccounts({
     </ConfirmDialog>
   );
 
-  if (error) {
-    return (
-      <Badge
-        tone="negative"
-        value="accounts unavailable"
-        title={error.detail ?? "listing linked accounts failed"}
-      />
-    );
+  // Shown as text, not a hover title. A list already loaded stays under a
+  // failed refetch, so a link or delete that worked is not hidden by a read
+  // that did not.
+  const errorPanel = error ? (
+    <ApiErrorPanel context="listing linked accounts failed" problem={error} />
+  ) : null;
+  if (accounts === null) {
+    return errorPanel ?? <span class="ui-linked-accounts-muted">…</span>;
   }
-  if (accounts === null) return <span class="ui-linked-accounts-muted">…</span>;
   if (accounts.length === 0) {
-    return <span class="ui-linked-accounts-muted">none linked</span>;
+    return (
+      <>
+        {errorPanel}
+        <span class="ui-linked-accounts-muted">none linked</span>
+      </>
+    );
   }
   return (
     <>
+      {errorPanel}
       <ul class="ui-linked-accounts">
         {accounts.map((a) => (
           <li key={`${a.kind}/${a.name}`}>