fix(core): use node: scoped builtin imports and add route unit tests

ts/core/utils/enhanced-connection-pool.ts

@@ -1,7 +1,7 @@
 import { LifecycleComponent } from './lifecycle-component.js';
 import { BinaryHeap } from './binary-heap.js';
 import { AsyncMutex } from './async-utils.js';
-import { EventEmitter } from 'events';
+import { EventEmitter } from 'node:events';
 
 /**
  * Interface for pooled connection