fix(watcher.node): Handle fs.watch close without spurious restarts; add tests and improve test runner

ts/watchers/watcher.node.ts

@@ -339,8 +339,9 @@ export class NodeWatcher implements IWatcher {
 
         // Handle 'close' event - fs.watch can close without error
         watcher.on('close', () => {
-          console.warn(`[smartwatch] FSWatcher closed unexpectedly for ${watchPath}`);
+          // Only log/restart if we didn't intentionally stop
           if (this._isWatching) {
+            console.warn(`[smartwatch] FSWatcher closed unexpectedly for ${watchPath}`);
             this.restartWatcher(watchPath, new Error('Watcher closed unexpectedly'));
           }
         });