Best practices app versioning, and extrame programming

[tg44]

I'm still in a learning phase so pls correct me if I'm wrong, or link the pages if it is written down somewhere that I haven't noticed.

A CI/CD pipeline with gitops has the following steps;
push/merge to master > run tests > build image > push image > try out image > persist image version to the ops repo

As I understand Argo can automate/assist the last step, it can detect if the app version is not the same as in the ops repo, and can write the ops repo, or rollback to it. The first three steps are also okay, I can do it with github-actions without a problem. The grey area is the versioning (what to push, how to tag the image that I push), and the try out stage. Is there any best practice for proper taging and registry cleaning, and registry to cluster hook?

Am I the only one who misses the registry tag listing and deploy from tags feature, as an app version handler board? I really need to commit to the ops repo, or manually update the image versions every time I push to a registry? Or are there other tools that supposed to close this gap?