fix(cron): suppress HEARTBEAT_OK summary from leaking into main session (#32013)

When an isolated cron agent returns HEARTBEAT_OK (nothing to announce),
the direct delivery is correctly skipped, but the fallback path in
timer.ts still enqueues the summary as a system event to the main
session. Filter out heartbeat-only summaries using isCronSystemEvent
before enqueuing, so internal ack tokens never reach user conversations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/cron/service.heartbeat-ok-summary-suppressed.test.ts

@@ -0,0 +1,111 @@
+import { describe, expect, it, vi } from "vitest";
+import { CronService } from "./service.js";
+import { setupCronServiceSuite, writeCronStoreSnapshot } from "./service.test-harness.js";
+import type { CronJob } from "./types.js";
+
+const { logger, makeStorePath } = setupCronServiceSuite({
+  prefix: "cron-heartbeat-ok-suppressed",
+});
+
+describe("cron isolated job HEARTBEAT_OK summary suppression (#32013)", () => {
+  it("does not enqueue HEARTBEAT_OK as a system event to the main session", async () => {
+    const { storePath } = await makeStorePath();
+    const now = Date.now();
+
+    const job: CronJob = {
+      id: "heartbeat-only-job",
+      name: "heartbeat-only-job",
+      enabled: true,
+      createdAtMs: now - 10_000,
+      updatedAtMs: now - 10_000,
+      schedule: { kind: "every", everyMs: 60_000 },
+      sessionTarget: "isolated",
+      wakeMode: "now",
+      payload: { kind: "agentTurn", message: "Check if anything is new" },
+      delivery: { mode: "announce" },
+      state: { nextRunAtMs: now - 1 },
+    };
+
+    await writeCronStoreSnapshot({ storePath, jobs: [job] });
+
+    const enqueueSystemEvent = vi.fn();
+    const requestHeartbeatNow = vi.fn();
+
+    const cron = new CronService({
+      storePath,
+      cronEnabled: true,
+      log: logger,
+      enqueueSystemEvent,
+      requestHeartbeatNow,
+      runHeartbeatOnce: vi.fn(),
+      // Simulate the isolated agent returning HEARTBEAT_OK — nothing to
+      // announce. The delivery was intentionally skipped.
+      runIsolatedAgentJob: vi.fn(async () => ({
+        status: "ok" as const,
+        summary: "HEARTBEAT_OK",
+        delivered: false,
+        deliveryAttempted: false,
+      })),
+    });
+
+    await cron.start();
+    await vi.advanceTimersByTimeAsync(2_000);
+    await vi.advanceTimersByTimeAsync(1_000);
+    cron.stop();
+
+    // HEARTBEAT_OK should NOT leak into the main session as a system event.
+    expect(enqueueSystemEvent).not.toHaveBeenCalled();
+    expect(requestHeartbeatNow).not.toHaveBeenCalled();
+  });
+
+  it("still enqueues real cron summaries as system events", async () => {
+    const { storePath } = await makeStorePath();
+    const now = Date.now();
+
+    const job: CronJob = {
+      id: "real-summary-job",
+      name: "real-summary-job",
+      enabled: true,
+      createdAtMs: now - 10_000,
+      updatedAtMs: now - 10_000,
+      schedule: { kind: "every", everyMs: 60_000 },
+      sessionTarget: "isolated",
+      wakeMode: "now",
+      payload: { kind: "agentTurn", message: "Check weather" },
+      delivery: { mode: "announce" },
+      state: { nextRunAtMs: now - 1 },
+    };
+
+    await writeCronStoreSnapshot({ storePath, jobs: [job] });
+
+    const enqueueSystemEvent = vi.fn();
+    const requestHeartbeatNow = vi.fn();
+
+    const cron = new CronService({
+      storePath,
+      cronEnabled: true,
+      log: logger,
+      enqueueSystemEvent,
+      requestHeartbeatNow,
+      runHeartbeatOnce: vi.fn(),
+      // Simulate real content that should be forwarded.
+      runIsolatedAgentJob: vi.fn(async () => ({
+        status: "ok" as const,
+        summary: "Weather update: sunny, 72°F",
+        delivered: false,
+        deliveryAttempted: false,
+      })),
+    });
+
+    await cron.start();
+    await vi.advanceTimersByTimeAsync(2_000);
+    await vi.advanceTimersByTimeAsync(1_000);
+    cron.stop();
+
+    // Real summaries SHOULD be enqueued.
+    expect(enqueueSystemEvent).toHaveBeenCalledWith(
+      expect.stringContaining("Weather update"),
+      expect.objectContaining({ agentId: undefined }),
+    );
+  });
+});

src/cron/service/timer.ts

@@ -1,4 +1,5 @@
 import type { CronConfig, CronRetryOn } from "../../config/types.cron.js";
+import { isCronSystemEvent } from "../../infra/heartbeat-events-filter.js";
 import type { HeartbeatRunResult } from "../../infra/heartbeat-wake.js";
 import { DEFAULT_AGENT_ID } from "../../routing/session-key.js";
 import { resolveCronDeliveryPlan } from "../delivery.js";
@@ -985,12 +986,17 @@ export async function executeJobCore(
   // ran. If delivery was attempted but final ack is uncertain, suppress the
   // main summary to avoid duplicate user-facing sends.
   // See: https://github.com/openclaw/openclaw/issues/15692
+  //
+  // Also suppress heartbeat-only summaries (e.g. "HEARTBEAT_OK") — these
+  // are internal ack tokens that should never leak into user conversations.
+  // See: https://github.com/openclaw/openclaw/issues/32013
   const summaryText = res.summary?.trim();
   const deliveryPlan = resolveCronDeliveryPlan(job);
   const suppressMainSummary =
     res.status === "error" && res.errorKind === "delivery-target" && deliveryPlan.requested;
   if (
     summaryText &&
+    isCronSystemEvent(summaryText) &&
     deliveryPlan.requested &&
     !res.delivered &&
     res.deliveryAttempted !== true &&