hi, following up on the reproducible builds pull request #151 , i would like to propose two additional changes in a separate pr.

first, adding a devbox.json file to pin the node.js version so all developers use the same environment, since different node.js versions can sometimes produce slightly different build outputs.

second, adding a small section to the readme that documents how to verify reproducible builds by running npm ci, building twice, and comparing file hashes.

please let me know if these additions would be welcome and i can submit them as a separate pull request to keep changes focused.