fix(cron): de-duplicate main-session heartbeat events

Fixes #44922

Preserve heartbeat-owned cron reminders as a single model input during heartbeat runs while keeping normal-turn fallback delivery when a heartbeat is skipped.

Proof: focused local Vitest/oxlint/format, clean autoreview, Crabbox AWS run_67abc286250a, Crabbox AWS check:changed run_bddebf014d58, and exact-head GitHub CI green for 341e807d7a.

src/auto-reply/reply/get-reply-run.ts

@@ -813,6 +813,7 @@ export async function runPreparedReply(
         sessionKey,
         isMainSession,
         isNewSession,
+        suppressHeartbeatOwnedEvents: isHeartbeat,
       });
       if (eventsBlock) {
         drainedSystemEventBlocks.push(eventsBlock);

src/auto-reply/reply/session-system-events.ts

@@ -18,8 +18,23 @@ import {
   type SystemEvent,
 } from "../../infra/system-events.js";
 
-function selectGenericSystemEvents(events: readonly SystemEvent[]): SystemEvent[] {
-  return events.filter((event) => !isExecCompletionEvent(event.text));
+function isCronContextSystemEvent(event: SystemEvent): boolean {
+  return event.contextKey?.startsWith("cron:") ?? false;
+}
+
+function selectGenericSystemEvents(
+  events: readonly SystemEvent[],
+  options?: { suppressHeartbeatOwnedEvents?: boolean },
+): SystemEvent[] {
+  // Exec completions and tagged cron events own dedicated heartbeat prompts
+  // (buildExecEventPrompt / buildCronEventPrompt). During heartbeat runs, leave
+  // cron entries queued for that owner; ordinary turns still drain them as the
+  // fallback when a heartbeat was skipped before it could consume the event.
+  return events.filter(
+    (event) =>
+      !isExecCompletionEvent(event.text) &&
+      !(options?.suppressHeartbeatOwnedEvents === true && isCronContextSystemEvent(event)),
+  );
 }
 
 function compactSystemEvent(line: string): string | null {
@@ -90,6 +105,7 @@ export async function drainFormattedSystemEvents(params: {
   sessionKey: string;
   isMainSession: boolean;
   isNewSession: boolean;
+  suppressHeartbeatOwnedEvents?: boolean;
 }): Promise<string | undefined> {
   const summaryLines: string[] = [];
   const systemLines: string[] = [];
@@ -97,7 +113,9 @@ export async function drainFormattedSystemEvents(params: {
   // so the heartbeat path can consume and deliver them.
   const queued = consumeSelectedSystemEventEntries(
     params.sessionKey,
-    selectGenericSystemEvents(peekSystemEventEntries(params.sessionKey)),
+    selectGenericSystemEvents(peekSystemEventEntries(params.sessionKey), {
+      suppressHeartbeatOwnedEvents: params.suppressHeartbeatOwnedEvents,
+    }),
   );
   for (const event of queued) {
     const compacted = compactSystemEvent(event.text);

src/auto-reply/reply/session.test.ts

@@ -3386,6 +3386,56 @@ describe("drainFormattedSystemEvents", () => {
       expect(line).toMatch(/^System:/);
     }
   });
+
+  it("leaves tagged cron events queued during heartbeat runs instead of re-rendering them (#44922)", async () => {
+    try {
+      // A `sessionTarget: "main"` cron systemEvent is enqueued tagged `cron:<jobId>`
+      // and is surfaced by the heartbeat's dedicated reminder prompt. The generic
+      // render must not also emit it as a raw `System:` line during that heartbeat
+      // run, or the model sees the same text twice.
+      enqueueSystemEvent("Reminder: rotate API keys", {
+        sessionKey: "agent:main:main",
+        contextKey: "cron:rotate-keys",
+      });
+      enqueueSystemEvent("Model switched.", { sessionKey: "agent:main:main" });
+
+      const result = await drainFormattedSystemEvents({
+        cfg: {} as OpenClawConfig,
+        sessionKey: "agent:main:main",
+        isMainSession: true,
+        isNewSession: false,
+        suppressHeartbeatOwnedEvents: true,
+      });
+
+      expect(result).toContain("Model switched.");
+      expect(result).not.toContain("rotate API keys");
+      // The cron event stays queued so the heartbeat path remains its single owner.
+      expect(peekSystemEvents("agent:main:main")).toEqual(["Reminder: rotate API keys"]);
+    } finally {
+      resetSystemEventsForTest();
+    }
+  });
+
+  it("renders tagged cron events on normal turns so skipped heartbeats still have a fallback", async () => {
+    try {
+      enqueueSystemEvent("Reminder: rotate API keys", {
+        sessionKey: "agent:main:main",
+        contextKey: "cron:rotate-keys",
+      });
+
+      const result = await drainFormattedSystemEvents({
+        cfg: {} as OpenClawConfig,
+        sessionKey: "agent:main:main",
+        isMainSession: true,
+        isNewSession: false,
+      });
+
+      expect(result).toContain("Reminder: rotate API keys");
+      expect(peekSystemEvents("agent:main:main")).toEqual([]);
+    } finally {
+      resetSystemEventsForTest();
+    }
+  });
 });
 
 describe("persistSessionUsageUpdate", () => {