Proposal pushes net/http toward finer form-parsing control

Damien Neild's proposal to give net/http and mime/multipart better control over form parsing leads the day, aiming at the long-standing awkwardness of handlers that transparently parse query and form data with little say in how. Two smaller API proposals ride alongside it: a bytes.Reader.Peek method, and a modernizer pass to rewrite ranging over Regexp.FindAllString in favour of the iterator forms arriving in Go 1.28. On the operational side, there's a solid writeup on why a preStop sleep is what finally stops a Kubernetes rollout from answering 503 to a chunk of in-flight requests, which pairs nicely with anyone who has stared at a graph wondering where those errors came from.