Contract versions

Blockchain is immutable, therefore the versioning is not supported. There is always only one version on the blockchain.

Upgradable Proxies

Even by upgrading the implementation for a contract. The previous implementation gets obsolete, so you have to reinstall the contract to regenerate the code.

Git versioning of the 0xweb/ folder

Unlike node_modules we suggest adding 0xweb folder with the generated classes to the project's repository. You can track later the changes made to the dAPPs (in case of proxies).
But you can also add 0xweb to .gitignore, as you can reinstall all contracts listed in 0xweb.json file any time later.