v0.5.49

• A Request or Response body may be any async iterable, as Node's fetch
  (undici) reads it: a Node stream, an http.IncomingMessage, an async
  generator, each chunk taken through Buffer.from as Node's is, an empty one
  passed over, and a stream already read or locked refused with undici's
  TypeError. The browser's constructors took such an object for a string
  ("[object Object]"). Next's App Router builds each route handler's request
  with the Node request as its body, so every POST a route handler read in a
  tab was that string: Dub's NextAuth credentials callback found no CSRF token
  and sent sign-in back to the login. A request with such a body and no
  duplex now throws, as Node's does, where the tab accepted it. fetch reads
  such a body the same way whichever transport answers it.
• A start script runs whole under a hosted program. A node on any line of
  a script (sh start.sh, sh -c 'a && node b') is a process of its own
  under the script's pid, where it was admitted under the shell's identity
  and its exit ended the script. sh and bash carry the run's name into
  the script they run, so its node is no longer refused for want of a
  named run, and pass over their own options (sh -e file). A shell a
  hosted program spawns runs at the host when there is one, where the
  page's programs (npx) are found. exec command runs the command with
  the script's environment.