fix(cron): share isolated announce flow + harden cron scheduling/delivery (#11641)

* fix(cron): comprehensive cron scheduling and delivery fixes

- Fix delivery target resolution for isolated agent cron jobs
- Improve schedule parsing and validation
- Add job retry logic and error handling
- Enhance cron ops with better state management
- Add timer improvements for more reliable cron execution
- Add cron event type to protocol schema
- Support cron events in heartbeat runner (skip empty-heartbeat check,
  use dedicated CRON_EVENT_PROMPT for relay)

* fix: remove cron debug test and add changelog/docs notes (#11641) (thanks @tyler6204)

src/agents/openclaw-tools.subagents.sessions-spawn-normalizes-allowlisted-agent-ids.test.ts

@@ -245,7 +245,7 @@ describe("openclaw-tools: subagents", () => {
       | undefined;
     expect(second?.sessionKey).toBe("discord:group:req");
     expect(second?.deliver).toBe(true);
-    expect(second?.message).toContain("background task");
+    expect(second?.message).toContain("subagent task");
 
     const sendCalls = calls.filter((c) => c.method === "send");
     expect(sendCalls.length).toBe(0);

src/agents/openclaw-tools.subagents.sessions-spawn-resolves-main-announce-target-from.test.ts

@@ -153,7 +153,7 @@ describe("openclaw-tools: subagents", () => {
     // Second call: main agent trigger (not "Sub-agent announce step." anymore)
     const second = agentCalls[1]?.params as { sessionKey?: string; message?: string } | undefined;
     expect(second?.sessionKey).toBe("main");
-    expect(second?.message).toContain("background task");
+    expect(second?.message).toContain("subagent task");
 
     // No direct send to external channel (main agent handles delivery)
     const sendCalls = calls.filter((c) => c.method === "send");

src/agents/subagent-announce.format.test.ts

@@ -94,7 +94,7 @@ describe("subagent announce formatting", () => {
     };
     const msg = call?.params?.message as string;
     expect(call?.params?.sessionKey).toBe("agent:main:main");
-    expect(msg).toContain("background task");
+    expect(msg).toContain("subagent task");
     expect(msg).toContain("failed");
     expect(msg).toContain("boom");
     expect(msg).toContain("Findings:");
@@ -155,7 +155,7 @@ describe("subagent announce formatting", () => {
     expect(didAnnounce).toBe(true);
     expect(embeddedRunMock.queueEmbeddedPiMessage).toHaveBeenCalledWith(
       "session-123",
-      expect.stringContaining("background task"),
+      expect.stringContaining("subagent task"),
     );
     expect(agentSpy).not.toHaveBeenCalled();
   });

src/agents/subagent-announce.ts

@@ -345,6 +345,8 @@ export type SubagentRunOutcome = {
   error?: string;
 };
 
+export type SubagentAnnounceType = "subagent task" | "cron job";
+
 export async function runSubagentAnnounceFlow(params: {
   childSessionKey: string;
   childRunId: string;
@@ -360,6 +362,7 @@ export async function runSubagentAnnounceFlow(params: {
   endedAt?: number;
   label?: string;
   outcome?: SubagentRunOutcome;
+  announceType?: SubagentAnnounceType;
 }): Promise<boolean> {
   let didAnnounce = false;
   try {
@@ -433,9 +436,10 @@ export async function runSubagentAnnounceFlow(params: {
             : "finished with unknown status";
 
     // Build instructional message for main agent
-    const taskLabel = params.label || params.task || "background task";
+    const announceType = params.announceType ?? "subagent task";
+    const taskLabel = params.label || params.task || "task";
     const triggerMessage = [
-      `A background task "${taskLabel}" just ${statusLabel}.`,
+      `A ${announceType} "${taskLabel}" just ${statusLabel}.`,
       "",
       "Findings:",
       reply || "(no output)",
@@ -443,7 +447,7 @@ export async function runSubagentAnnounceFlow(params: {
       statsLine,
       "",
       "Summarize this naturally for the user. Keep it brief (1-2 sentences). Flow it into the conversation naturally.",
-      "Do not mention technical details like tokens, stats, or that this was a background task.",
+      `Do not mention technical details like tokens, stats, or that this was a ${announceType}.`,
       "You can respond with NO_REPLY if no announcement is needed (e.g., internal task with no user-facing result).",
     ].join("\n");