Additional Ports and Shen Tooling

[Reuben]

I've been hacking away using Shen on lots of different projects -- will try to share some as I get further. 

Meanwhile, I wanted to share a couple additional ports (PR here: https://github.com/Shen-Language/shen-language.github.io/pull/13) and I’ve also been building two cross-port tools:

* Bifrost (https://github.com/pyrex41/bifrost) runs the same Shen expressions and programs across multiple implementations, compares their behavior, and can act as a front door for selecting a specific port. Sort of like Roswell, but for Shen
* Ratatoskr (https://github.com/pyrex41/ratatoskr) tree-shakes Shen programs and builds standalone artifacts for several hosts.

All of these should currently be considered experimental. The ports are targeting Shen kernel 41.2, and they still need broader real-world testing—particularly on Windows. Feedback, portability reports, and test programs would be very welcome.

[Reuben]

I've found `bifrost` to be particularly useful for finding bugs / issues with the various ports, because it makes it easy to run a program from any port, or set up tests beyond the standard Shen test suite to validate the ports.

It's also been very useful for working with AI in cloud container environments -- I can tell claude code web to look at the bifrost repo on github, and then use it to set up a specific Shen port in it's environment. The Go port has been particularly useful for this.