chore: standardize on Yarn + Node 22.21.1 across CI, Docker, and README#1

Copilot wants to merge 4 commits into

mainMedalcode/Toallaalacarta:mainfrom

copilot/standardize-repo-with-yarnMedalcode/Toallaalacarta:copilot/standardize-repo-with-yarnCopy head branch name to clipboard