runner-wrapper: buffer errCh to avoid goroutine leak on shutdown

The wrapper start() goroutine always sends exactly one error
into errCh. When Run() exits early due to context cancellation,
the unbuffered channel could block the sender forever.

Make errCh buffered (size 1) to ensure the start goroutine
can always complete and exit cleanly.

No behavior change under normal execution.

Author: Emmanuel326

helpers/runner_wrapper/wrapper.go

@@ -49,7 +49,7 @@ func New(log logrus.FieldLogger, path string, args []string) *Wrapper {
 		log:                log,
 		path:               path,
 		args:               args,
-		errCh:              make(chan error),
+		errCh:              make(chan error, 1),
 		terminationTimeout: DefaultTerminationTimeout,
 		status:             api.StatusUnknown,
 		commanderFactory:   newDefaultCommander,