fix/heartbeat ok delivery filter (#246)

* cron: skip delivery for HEARTBEAT_OK responses

When an isolated cron job has deliver:true, skip message delivery if the
response is just HEARTBEAT_OK (or contains HEARTBEAT_OK at edges with
short remaining content <= 30 chars). This allows cron jobs to silently
ack when nothing to report but still deliver actual content when there
is something meaningful to say.

Media is still delivered even if text is HEARTBEAT_OK, since the
presence of media indicates there's something to share.

* fix(heartbeat): make ack padding configurable

* chore(deps): update to latest

---------

Co-authored-by: Josh Lehman <josh@martian.engineering>

src/infra/heartbeat-runner.test.ts

@@ -181,6 +181,64 @@ describe("runHeartbeatOnce", () => {
     }
   });
 
+  it("respects ackMaxChars for heartbeat acks", async () => {
+    const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-hb-"));
+    const storePath = path.join(tmpDir, "sessions.json");
+    const replySpy = vi.spyOn(replyModule, "getReplyFromConfig");
+    try {
+      await fs.writeFile(
+        storePath,
+        JSON.stringify(
+          {
+            main: {
+              sessionId: "sid",
+              updatedAt: Date.now(),
+              lastChannel: "whatsapp",
+              lastTo: "+1555",
+            },
+          },
+          null,
+          2,
+        ),
+      );
+
+      const cfg: ClawdbotConfig = {
+        agent: {
+          heartbeat: {
+            every: "5m",
+            target: "whatsapp",
+            to: "+1555",
+            ackMaxChars: 0,
+          },
+        },
+        whatsapp: { allowFrom: ["*"] },
+        session: { store: storePath },
+      };
+
+      replySpy.mockResolvedValue({ text: "HEARTBEAT_OK 🦞" });
+      const sendWhatsApp = vi.fn().mockResolvedValue({
+        messageId: "m1",
+        toJid: "jid",
+      });
+
+      await runHeartbeatOnce({
+        cfg,
+        deps: {
+          sendWhatsApp,
+          getQueueSize: () => 0,
+          nowMs: () => 0,
+          webAuthExists: async () => true,
+          hasActiveWebListener: () => true,
+        },
+      });
+
+      expect(sendWhatsApp).toHaveBeenCalled();
+    } finally {
+      replySpy.mockRestore();
+      await fs.rm(tmpDir, { recursive: true, force: true });
+    }
+  });
+
   it("skips WhatsApp delivery when not linked or running", async () => {
     const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-hb-"));
     const storePath = path.join(tmpDir, "sessions.json");

src/infra/heartbeat-runner.ts

@@ -1,5 +1,6 @@
 import { chunkText, resolveTextChunkLimit } from "../auto-reply/chunk.js";
 import {
+  DEFAULT_HEARTBEAT_ACK_MAX_CHARS,
   HEARTBEAT_PROMPT,
   stripHeartbeatToken,
 } from "../auto-reply/heartbeat.js";
@@ -102,6 +103,13 @@ export function resolveHeartbeatPrompt(cfg: ClawdbotConfig) {
   return trimmed || HEARTBEAT_PROMPT;
 }
 
+function resolveHeartbeatAckMaxChars(cfg: ClawdbotConfig) {
+  return Math.max(
+    0,
+    cfg.agent?.heartbeat?.ackMaxChars ?? DEFAULT_HEARTBEAT_ACK_MAX_CHARS,
+  );
+}
+
 function resolveHeartbeatSession(cfg: ClawdbotConfig) {
   const sessionCfg = cfg.session;
   const scope = sessionCfg?.scope ?? "per-sender";
@@ -277,11 +285,12 @@ async function restoreHeartbeatUpdatedAt(params: {
 
 function normalizeHeartbeatReply(
   payload: ReplyPayload,
-  responsePrefix?: string,
+  responsePrefix: string | undefined,
+  ackMaxChars: number,
 ) {
   const stripped = stripHeartbeatToken(payload.text, {
     mode: "heartbeat",
-    maxAckChars: 30,
+    maxAckChars: ackMaxChars,
   });
   const hasMedia = Boolean(
     payload.mediaUrl || (payload.mediaUrls?.length ?? 0) > 0,
@@ -478,9 +487,11 @@ export async function runHeartbeatOnce(opts: {
       return { status: "ran", durationMs: Date.now() - startedAt };
     }
 
+    const ackMaxChars = resolveHeartbeatAckMaxChars(cfg);
     const normalized = normalizeHeartbeatReply(
       replyPayload,
       cfg.messages?.responsePrefix,
+      ackMaxChars,
     );
     if (normalized.shouldSkip && !normalized.hasMedia) {
       await restoreHeartbeatUpdatedAt({