process.listenerCount(event, listener) reports incorrect counts under CLI

[ShiroKSH]

Description

The CLI installs hidden SIGINT and SIGTERM relay listeners and wraps process.listenerCount() so those internal listeners are not visible. The wrapper currently subtracts one from every count for those signals, including the listenerCount(eventName, listener) overload and cases where the hidden listener has already been removed.

Reproduction

const handler = () => {};
process.on('SIGINT', handler);

setTimeout(() => {
	console.log(process.listenerCount('SIGINT', handler));
	process.removeAllListeners('SIGINT');
	console.log(process.listenerCount('SIGINT'));
}, 100);

With Node v24.18.0:

$ node repro.js
1
0

With the current tsx master (5828ffe):

$ tsx repro.js
0
-1

Expected behavior

Specific user-listener counts should match Node, aggregate counts should never become negative, and the internal relay listener should remain hidden while it is installed.