socialistlight-ctrl/MERN-Stack-2 ? reverse-engineered prompt

Build me a small JavaScript practice repo with a separate file for each simple exercise, like finding the sum of an array, checking even and odd numbers, filtering even numbers, finding the largest value, printing numbers up to 10, merging arrays, reversing a string or array, a loop based reward style example, and a template literal example.

I want each file to be easy to read, with plain solution code and a short comment at the top saying what it does. Keep it simple and beginner friendly, like something I could use to study basic JavaScript logic. If it helps, make sure the examples run cleanly in Node and use straightforward variables and loops instead of fancy patterns.