Github doesn’t do any signing at all nor do they rally care about the actual output of actions, pipelines or manual releases (all of that is out of their interest scope).

If there’s any means of a ‘secret store’ for the build actions then you could store a keypair for signing the binaries as far as your target binary format and platforms support it (or go for something like a detached gpg-signature that can be stored with the build or in a central ‘trusted’ repository so the binary can be verified against it later).

You users however would still have no easy means to verify that signature on most platforms unless they are tech-savvy. (macOS code signing / notarization and gatekeeper check would be an example of a platform that would notify users and even fail to run the binary if it was tampered with).

My one concern with this idea is that it requires a lot of wrist/arm movement away from the home row and main area of the keyboard.

You have all of the major programming symbols on here - which is great - but also implies that you’d remove your right hand from it’s main position in the right half of the keyboard to reach to the number pad, then move back, find the home row, keep typing, repeat, etc.

That feels a lot more clunky and unnecessary than pressing alt-gr/shift/option+key on most regular layouts IMO.

(This isn’t meant to be a harsh criticism, I love the idea to make a more useful numerpad but given where a number pad is located it doesn’t feel like it would help typing efficiency for coding at all)