Hello,
I've read completely what you need and I have required skill and time to work with you. Both on this project and in long time.
I have knowledge of git, npm and es6 since I do all of back end work in node.js using latest, ES6, standards.
Unfortunately I don't have any games developed by Phaser at the moment to show you, but I'm very familiar with it since I was doing some work in the past using it.
My timezone is UTC+2h and I can work from 10am to 6pm.
Sincerely,
Andrija