[Part 5/6] feat(telemetry): add activity monitor with event-driven snapshots (#8124)

Co-authored-by: Jacob Richman <jacob314@gmail.com>

packages/core/src/telemetry/index.ts

@@ -87,6 +87,13 @@ export {
   recordUserActivity,
   isUserActive,
 } from './activity-detector.js';
+export {
+  ActivityMonitor,
+  initializeActivityMonitor,
+  getActivityMonitor,
+  startGlobalActivityMonitoring,
+  stopGlobalActivityMonitoring,
+} from './activity-monitor.js';
 export {
   // Core metrics functions
   recordToolCallMetrics,