Heartbeat every 30s while waiting on the approval workflow

The approval handler blocks on handle.result() for as long as the
operator takes to decide. agenticSession only heartbeats between LLM
turns, so a multi-hour wait inside this handler would trigger
heartbeat timeout (default 120s) and kill the activity.

setInterval fires heartbeat() every 30s, cleared in finally when
handle.result() returns. Survives realistic operator delays.

Existing tests still pass (the test path uses a fake deps record
that doesn't go through this code path).

Author: lex00

tool-registry-incident-triage/src/activities/triage.ts

@@ -20,6 +20,7 @@
  */
 import { exec } from "node:child_process";
 import { promisify } from "node:util";
+import { heartbeat } from "@temporalio/activity";
 import { Connection, Client } from "@temporalio/client";
 import { WorkflowIdConflictPolicy } from "@temporalio/common";
 import { ToolRegistry, agenticSession, type AgenticSession } from "@temporalio/tool-registry";
@@ -316,7 +317,16 @@ async function realRequestHumanApproval(alert: AlertPayload, request: ApprovalRe
     workflowIdConflictPolicy: WorkflowIdConflictPolicy.USE_EXISTING,
   });
 
-  const response = (await handle.result()) as ApprovalResponse;
-  await connection.close();
-  return response;
+  // Heartbeat every 30 seconds while waiting on the approval workflow.
+  // agenticSession only heartbeats between LLM turns, so a multi-hour
+  // operator wait inside this handler would otherwise trigger heartbeat
+  // timeout in 120s and kill the activity.
+  const ticker = setInterval(() => heartbeat(), 30_000);
+  try {
+    const response = (await handle.result()) as ApprovalResponse;
+    return response;
+  } finally {
+    clearInterval(ticker);
+    await connection.close();
+  }
 }