Fedi is not the protocol. Fedimint is the protocol. Fedi is just a company. Fedi software is not open source.
Discussion
You're right on the protocol name, it slipped my mind. I stand corrected.
I was also unable to find source code for the alpha release of the app. The backend source code is available though.
That's strange.
Do you know if there are plans to release the frontend app source?
https://github.com/fedibtc/fedi-alpha
Fedi recently open-sourced their app