fix(cron): notify user when cron job is auto-disabled after repeated errors (openclaw#29098) thanks @ningding97

Verified:
- pnpm install --frozen-lockfile
- pnpm check
- pnpm test -- --run src/cron/service.runs-one-shot-main-job-disables-it.test.ts

Co-authored-by: ningding97 <17723822+ningding97@users.noreply.github.com>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

src/cron/service/jobs.ts

@@ -208,6 +208,19 @@ function recordScheduleComputeError(params: {
       { jobId: job.id, name: job.name, errorCount, err: errText },
       "cron: auto-disabled job after repeated schedule errors",
     );
+
+    // Notify the user so the auto-disable is not silent (#28861).
+    const notifyText = `⚠️ Cron job "${job.name}" has been auto-disabled after ${errorCount} consecutive schedule errors. Last error: ${errText}`;
+    state.deps.enqueueSystemEvent(notifyText, {
+      agentId: job.agentId,
+      sessionKey: job.sessionKey,
+      contextKey: `cron:${job.id}:auto-disabled`,
+    });
+    state.deps.requestHeartbeatNow({
+      reason: `cron:${job.id}:auto-disabled`,
+      agentId: job.agentId,
+      sessionKey: job.sessionKey,
+    });
   } else {
     state.deps.log.warn(
       { jobId: job.id, name: job.name, errorCount, err: errText },