Modernization with AI tools project 2026

Major steps

✅move to git
e2e tests working and thorough coverage
front end using very outdated an eol frameworks and libraries, modernize as much as possible without breaking changes
front end has my probably crappy javascript coded throughout probably can be refactored bigly need advice, want to be able to add new features quickly and easily and still work without breaking anyone's usage. Much like the backend I copy pasted over and over rather than refactoring when I should have to reduce the code surface area through refactoring
Back end has some outdated dependencies, older .net 8 now it's 10 I think, when is the eol, don't want to force people to have to upgrade the .net environment, need advice on that, should I be bundling the dependencies instead of relying on external framework, ask the ai
Back end has an enormous amount of copy/paste identical code throughout just grew that way, want to reduce the code size dramatically and refactor with the help of ai, could reduce it by a huge factor I think and shrink the footprint / exposure whatever the term is
TEST ALL THE THINGS: There are no automated tests beyond the e2e of any note, just a very outdated xunit integration test used during development, I would like automated testing everywhere that it makes sense, but after the refactor because it will reduce the amount of tests required