mu 3.11.2

mu_delegate accepts model ids it used to refuse.
Upgrade with npm i -g @mu-crew/mu@3.11.2, then /reload in running
pi sessions to pick up the extension. No schema change.

Changed

• mu_delegate is forgiving about model. It used to refuse any
  value outside [A-Za-z0-9._:/@+-], so real ids such as
  modelbridge/meta-openai/gpt-6.1-sol[1m]:high were rejected, and
  that happened in 12 past sessions. It now trims whitespace, drops
  surrounding quotes or backticks and a pasted --model / --model=
  prefix, and shell-quotes any other value inside --command, so pi
  decides whether the id exists. An empty model counts as unset. The
  only value still refused is one with whitespace inside it.