would be useful to be able to create tags directly

As well as the existing tag operations, I am finding in the conversion projects I have been working on that I need to essentially synthesise tags on commits that don't have them. I have been doing that with horrible combinations of adding fileops, split, tagify, etc. but it's pretty ugly.

It would be nice to have a tag X create operation on a commit to create a tag on a commit. The ability to make either a lightweight tag or an annotated tag as appropriate, and to be able to specify the tag date, would be desirable too.