feat(settings): move utility agents to main agents page (#436)

* feat(settings): move utility agents to main agents page

- Extract utility agents section into reusable component
- Add utility agents section to main agents settings page
- Remove separate utility agents page and sidebar link
- Consolidate all agent-related settings in one location

* style: format utility-agents-section.tsx with prettier

* fix: add error handling for utility agents operations

- Add try/catch with rollback for handleDefaultChange
- Add try/catch for onDelete to prevent UI inconsistency on failure

Addresses CodeRabbit review comments.

apps/web/app/settings/agents/page.tsx

@@ -29,6 +29,7 @@ import { useAgentDiscovery } from "@/hooks/domains/settings/use-agent-discovery"
 import { useAvailableAgents } from "@/hooks/domains/settings/use-available-agents";
 import { AgentLogo } from "@/components/agent-logo";
 import { AddTUIAgentDialog } from "@/components/settings/add-tui-agent-dialog";
+import { UtilityAgentsSection } from "@/components/settings/utility-agents-section";
 import { toAgentProfileOption } from "@/lib/state/slices/settings/types";
 import type {
   AgentDiscovery,
@@ -565,6 +566,8 @@ export default function AgentsSettingsPage() {
 
       <ConfigChatAgentSection />
 
+      <UtilityAgentsSection />
+
       <AddTUIAgentDialog
         open={tuiDialogOpen}
         onOpenChange={setTuiDialogOpen}

apps/web/components/settings/settings-app-sidebar.tsx

@@ -14,7 +14,6 @@ import {
   IconMessageCircle,
   IconBrandGithub,
   IconSparkles,
-  IconWand,
 } from "@tabler/icons-react";
 import {
   Sidebar,
@@ -299,16 +298,6 @@ export function SettingsAppSidebar() {
                   </SidebarMenuButton>
                 </SidebarMenuItem>
 
-                {/* Utility Agents */}
-                <SidebarMenuItem>
-                  <SidebarMenuButton asChild isActive={pathname === "/settings/utility"}>
-                    <Link href="/settings/utility">
-                      <IconWand className="h-4 w-4" />
-                      <span>Utility Agents</span>
-                    </Link>
-                  </SidebarMenuButton>
-                </SidebarMenuItem>
-
                 <ExecutorsSidebarSection pathname={pathname} executors={executors} />
                 <SecretsSidebarSection pathname={pathname} />
 

apps/web/components/settings/utility-agents-section.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useEffect, useState, useCallback, useMemo } from "react";
+import { useCallback, useEffect, useMemo, useState } from "react";
 import { Separator } from "@kandev/ui/separator";
 import {
   listUtilityAgents,
@@ -43,7 +43,7 @@ async function handleBuiltinChange(
   );
 }
 
-export default function UtilityAgentsSettingsPage() {
+export function UtilityAgentsSection() {
   const [agents, setAgents] = useState<UtilityAgent[]>([]);
   const [inferenceAgents, setInferenceAgents] = useState<InferenceAgent[]>([]);
   const [defaultAgentId, setDefaultAgentId] = useState("");
@@ -75,14 +75,17 @@ export default function UtilityAgentsSettingsPage() {
     }
   }, []);
 
-  useEffect(() => {
-    fetchData();
-  }, [fetchData]);
-
   const handleDefaultChange = async (agentId: string, model: string) => {
+    const prevAgentId = defaultAgentId;
+    const prevModel = defaultModel;
     setDefaultAgentId(agentId);
     setDefaultModel(model);
-    await updateUserSettings({ default_utility_agent_id: agentId, default_utility_model: model });
+    try {
+      await updateUserSettings({ default_utility_agent_id: agentId, default_utility_model: model });
+    } catch {
+      setDefaultAgentId(prevAgentId);
+      setDefaultModel(prevModel);
+    }
   };
 
   const openEditDialog = (agent: UtilityAgent | null) => {
@@ -96,46 +99,55 @@ export default function UtilityAgentsSettingsPage() {
     fetchData();
   };
 
-  if (loading)
-    return <div className="py-8 text-center text-muted-foreground text-sm">Loading...</div>;
+  useEffect(() => {
+    fetchData();
+  }, [fetchData]);
+
+  if (loading) return null;
 
   return (
-    <div className="space-y-8">
-      <header>
-        <h2 className="text-xl font-semibold">Utility Agents</h2>
-        <p className="text-sm text-muted-foreground">
-          One-shot AI helpers for commits, PRs, and prompts.
-        </p>
-      </header>
-      <Separator />
-      <DefaultModelSection
-        inferenceAgents={inferenceAgents}
-        defaultAgentId={defaultAgentId}
-        defaultModel={defaultModel}
-        onDefaultChange={handleDefaultChange}
-      />
-      <PerActionOverridesSection
-        builtins={builtins}
-        allModels={allModels}
-        defaultModel={defaultModel}
-        onModelChange={(agent, value) => handleBuiltinChange(agent, value, setAgents)}
-        onEdit={openEditDialog}
-      />
-      <CustomAgentsSection
-        agents={customAgents}
-        onAdd={() => openEditDialog(null)}
-        onEdit={openEditDialog}
-        onDelete={async (agent) => {
-          await deleteUtilityAgent(agent.id);
-          setAgents((prev) => prev.filter((a) => a.id !== agent.id));
-        }}
-      />
+    <>
+      <div className="space-y-4">
+        <Separator />
+        <div>
+          <h3 className="text-lg font-semibold">Utility Agents</h3>
+          <p className="text-sm text-muted-foreground">
+            One-shot AI helpers for commits, PRs, and prompts.
+          </p>
+        </div>
+        <DefaultModelSection
+          inferenceAgents={inferenceAgents}
+          defaultAgentId={defaultAgentId}
+          defaultModel={defaultModel}
+          onDefaultChange={handleDefaultChange}
+        />
+        <PerActionOverridesSection
+          builtins={builtins}
+          allModels={allModels}
+          defaultModel={defaultModel}
+          onModelChange={(agent, value) => handleBuiltinChange(agent, value, setAgents)}
+          onEdit={openEditDialog}
+        />
+        <CustomAgentsSection
+          agents={customAgents}
+          onAdd={() => openEditDialog(null)}
+          onEdit={openEditDialog}
+          onDelete={async (agent) => {
+            try {
+              await deleteUtilityAgent(agent.id);
+              setAgents((prev) => prev.filter((a) => a.id !== agent.id));
+            } catch {
+              // Error already logged by API layer
+            }
+          }}
+        />
+      </div>
       <UtilityAgentDialog
         open={dialogOpen}
         onOpenChange={setDialogOpen}
         agent={editingAgent}
         onSuccess={closeDialog}
       />
-    </div>
+    </>
   );
 }