Small nit: Maybe not say what YOU are doing, but what the COMMIT, when applied, will do. Git is not a personal work log, it's a source code change log. A commit may be a collaborative effort; it may be a squash of a thousand smaller commits; it may be a merge, it may be generated by a tool (like the dependencies), etc.
The commit should summarize what IT does, not what YOU did. In ten years, nobody will care who you are or what you did, but they will care what the code does and why.
> That's the main reason we are using present tense in commit messages, not past tense.
As a linguistic note, commit messages (at least, English commit messages) almost always use an infinitive verb and therefore may be considered to have no tense at all, though to argue that infinitives have no tense you do need to draw a distinction between tense and aspect.
> I believe it’s the imperative (enable widget) not the infinitive (to enable widget)
You're confusing a bare infinitive with an imperative. Infinitives are often, but not always, marked with to. Commit messages are not commands and are not capable of licensing imperative forms.
Here are some examples of bare infinitives in English, with the infinitive form italicized:
1. This organization will help you apply for a loan.
2a. Q: What does he do?
2b. A: Check over the paperwork to be sure everything's right.
A commit message is doing exactly the same thing as occurs in example 2b.
The commit should summarize what IT does, not what YOU did. In ten years, nobody will care who you are or what you did, but they will care what the code does and why.