Struct-by-value beats pointers in a hot path, and autocert eyes P-384

The liveliest thread of the day comes from an engineer profiling a high-throughput backend and finding that passing structs by value outperformed passing pointers through their call chain, which is the sort of result that tends to overturn a lot of received C/C++ instinct. It pairs neatly with a separate discussion digging into GC shape stenciling and why Go's generics implementation makes those sorts of costs less obvious than they look. On the proposal tracker, there is a request to let x/crypto/acme/autocert issue ECDSA P-384 certificates for CNSA 2.0 compatibility, alongside a smaller ask to make the per-test fuzz timeout configurable.