This is a hodgepodge of minor updates to various parts of the jsg code to modernize a bit where appropriate, fixup minor issues (like typos, duplications, dead code, etc), de-deduplicate a bit, etc. I'd been working through a few of these manually but decided to see if claude could handle it and it actually did a pretty good job. About half of the suggested improvements it came up with were fairly silly tho so I ended up ignoring about half of what it came up with. Still, a good exercise. The vast majority of these will not be functional changes and those that are should only impact compile time.