I'm working with Rust first time, it's my new experience in desktop development also (GTK mostly). Application I'm writing get grow and I think it's a good time to begin cover interface strings into some wrapper, to make simple extract and sync with Crowdin later.
Before, I have used Symfony, with it CLI tool, that provides API in few clicks. But what about Rust, to not read a lot. It could be some common, most useful way here or maybe the crate or std asset, where I can start integration from.
I'd expect rust_i18n to be of interest for you. It supports custom backends which you could use to create a Crowdin integration through their REST API.