fix(watcher): unref lingering FSWatcher handles after stopping the node watcher

ts/watchers/watcher.node.ts

@@ -90,6 +90,14 @@ export class NodeWatcher implements IWatcher {
       this.watcher = null;
     }
 
+    // Unref any lingering FSWatcher handles from chokidar so they don't prevent process exit.
+    // Chokidar v5's close() resolves before all fs.watch() handles are fully released.
+    for (const handle of (process as any)._getActiveHandles()) {
+      if (handle?.constructor?.name === 'FSWatcher' && typeof handle.unref === 'function') {
+        handle.unref();
+      }
+    }
+
     this._isWatching = false;
     console.log('[smartwatch] Watcher stopped');
   }