Disable timer heartbeats by default for new agents

ui/src/components/AgentConfigForm.tsx

@@ -923,14 +923,14 @@ export function AgentConfigForm(props: AgentConfigFormProps) {
               <ToggleWithNumber
                 label="Heartbeat on interval"
                 hint={help.heartbeatInterval}
-                checked={eff("heartbeat", "enabled", heartbeat.enabled !== false)}
+                checked={eff("heartbeat", "enabled", heartbeat.enabled === true)}
                 onCheckedChange={(v) => mark("heartbeat", "enabled", v)}
                 number={eff("heartbeat", "intervalSec", Number(heartbeat.intervalSec ?? 300))}
                 onNumberChange={(v) => mark("heartbeat", "intervalSec", v)}
                 numberLabel="sec"
                 numberPrefix="Run heartbeat every"
                 numberHint={help.intervalSec}
-                showNumber={eff("heartbeat", "enabled", heartbeat.enabled !== false)}
+                showNumber={eff("heartbeat", "enabled", heartbeat.enabled === true)}
               />
             </div>
             <CollapsibleSection

ui/src/components/OnboardingWizard.tsx

@@ -33,6 +33,7 @@ import {
   buildOnboardingProjectPayload,
   selectDefaultCompanyGoalId
 } from "../lib/onboarding-launch";
+import { buildNewAgentRuntimeConfig } from "../lib/new-agent-runtime-config";
 import {
   DEFAULT_CODEX_LOCAL_BYPASS_APPROVALS_AND_SANDBOX,
   DEFAULT_CODEX_LOCAL_MODEL
@@ -460,15 +461,7 @@ export function OnboardingWizard() {
         role: "ceo",
         adapterType,
         adapterConfig: buildAdapterConfig(),
-        runtimeConfig: {
-          heartbeat: {
-            enabled: true,
-            intervalSec: 3600,
-            wakeOnDemand: true,
-            cooldownSec: 10,
-            maxConcurrentRuns: 1
-          }
-        }
+        runtimeConfig: buildNewAgentRuntimeConfig()
       });
       setCreatedAgentId(agent.id);
       queryClient.invalidateQueries({

ui/src/lib/new-agent-runtime-config.test.ts

@@ -0,0 +1,34 @@
+// @vitest-environment node
+import { describe, expect, it } from "vitest";
+import { buildNewAgentRuntimeConfig } from "./new-agent-runtime-config";
+
+describe("buildNewAgentRuntimeConfig", () => {
+  it("defaults new agents to no timer heartbeat", () => {
+    expect(buildNewAgentRuntimeConfig()).toEqual({
+      heartbeat: {
+        enabled: false,
+        intervalSec: 300,
+        wakeOnDemand: true,
+        cooldownSec: 10,
+        maxConcurrentRuns: 1,
+      },
+    });
+  });
+
+  it("preserves explicit heartbeat settings", () => {
+    expect(
+      buildNewAgentRuntimeConfig({
+        heartbeatEnabled: true,
+        intervalSec: 3600,
+      }),
+    ).toEqual({
+      heartbeat: {
+        enabled: true,
+        intervalSec: 3600,
+        wakeOnDemand: true,
+        cooldownSec: 10,
+        maxConcurrentRuns: 1,
+      },
+    });
+  });
+});

ui/src/lib/new-agent-runtime-config.ts

@@ -0,0 +1,16 @@
+import { defaultCreateValues } from "../components/agent-config-defaults";
+
+export function buildNewAgentRuntimeConfig(input?: {
+  heartbeatEnabled?: boolean;
+  intervalSec?: number;
+}) {
+  return {
+    heartbeat: {
+      enabled: input?.heartbeatEnabled ?? defaultCreateValues.heartbeatEnabled,
+      intervalSec: input?.intervalSec ?? defaultCreateValues.intervalSec,
+      wakeOnDemand: true,
+      cooldownSec: 10,
+      maxConcurrentRuns: 1,
+    },
+  };
+}

ui/src/pages/NewAgent.tsx

@@ -23,6 +23,7 @@ import { getUIAdapter, listUIAdapters } from "../adapters";
 import { useDisabledAdaptersSync } from "../adapters/use-disabled-adapters";
 import { isValidAdapterType } from "../adapters/metadata";
 import { ReportsToPicker } from "../components/ReportsToPicker";
+import { buildNewAgentRuntimeConfig } from "../lib/new-agent-runtime-config";
 import {
   DEFAULT_CODEX_LOCAL_BYPASS_APPROVALS_AND_SANDBOX,
   DEFAULT_CODEX_LOCAL_MODEL,
@@ -175,15 +176,10 @@ export function NewAgent() {
       ...(selectedSkillKeys.length > 0 ? { desiredSkills: selectedSkillKeys } : {}),
       adapterType: configValues.adapterType,
       adapterConfig: buildAdapterConfig(),
-      runtimeConfig: {
-        heartbeat: {
-          enabled: configValues.heartbeatEnabled,
-          intervalSec: configValues.intervalSec,
-          wakeOnDemand: true,
-          cooldownSec: 10,
-          maxConcurrentRuns: 1,
-        },
-      },
+      runtimeConfig: buildNewAgentRuntimeConfig({
+        heartbeatEnabled: configValues.heartbeatEnabled,
+        intervalSec: configValues.intervalSec,
+      }),
       budgetMonthlyCents: 0,
     });
   }