Add worker.unref() to prevent test hangs

The worker pool was causing Jest to hang because the worker thread
prevented Node from exiting. Using unref() allows Node to exit even
if the worker is still running, which is safe since the worker is
lazily created and terminated on app quit.

This fixes the integration test failures where tests would timeout
waiting for the process to exit.

Author: ammar-agent

src/services/tokenizerWorkerPool.ts

@@ -47,6 +47,9 @@ class TokenizerWorkerPool {
     this.worker = new Worker(workerPath);
     this.isTerminating = false;
 
+    // Allow Node to exit even if worker is still running (important for tests)
+    this.worker.unref();
+
     this.worker.on("message", (response: TokenizeResponse) => {
       this.handleResponse(response);
     });