[brson]

Rust borrow checker author's new language designs.

Follow up posts:

https://smallcultfollowing.com/babysteps/blog/2026/02/09/hel...

https://smallcultfollowing.com/babysteps/blog/2026/02/10/dad...

https://smallcultfollowing.com/babysteps/blog/2026/02/14/sha...