Proposal targets ASCII ToUpper/ToLower in strings package

A proposal to speed up the ASCII paths of strings.ToUpper and ToLower by writing directly into a buffer instead of going through Builder leads the day, with a CL already up for review. Around it, the writing skews practical: a walkthrough of concurrency fundamentals making the rounds on Lobsters, a field report on running a deploy tool in production and finding the bug only prod could surface, and a piece on why connection pools and shared caches quietly misbehave. On the sillier end, someone wired a local llama.cpp-in-Go model into a program that roasts their room, which is at least an honest use of an afternoon.