I wrote a pass-like password manager that's built using a layered architecture and one of the lower layers basically fits your exact use-case! The three layers that make up the password manager are:
- securestore - An encrypted file store
- vcstore - A version controlled file store
- pass - Password manager functionality
Each layer builds on the last, so in your case, you could just use the vcstore layer directly without the password manager functionality. I wrote a blog post on it[1] if it sounds interesting.
I love the simplicity of Pass, but I wanted just a few more features, like being able to store (and retrieve) extra data easily. Unstructured data below the initial password wasn't really enough for me.
I ended up taking huge inspiration from Pass, but writing my own implementation[1] with a few more features that increased it's usefulness for my use cases.
I posted it a while ago on here[2] and Reddit[3], but it basically stores each entry as a Bash script, which gives it so much flexibility: auto-typing, references, multiple fields, executable functions, etc. I also wrote a blog post on it[4].
I'd be interested to hear what people think of if if anyone did/does end up giving it a go.