v0.2.2: ship the argv-leak and keychain-account fixes

Fixed

• The keychain account name was documented as <login-id>, with a note saying it
  could be any label. It cannot: the wrapper and the server both look up
  ${NTUCOOL_ACCOUNT:-default}, so a token stored under a login-id is simply not
  found. Anyone following the setup instructions literally ended up with a token
  the server could not read. Now documented as default, with the override
  described as a lookup key rather than a label.

• Every example passed the token as -w <token>, which places it in the process
  argument list for the lifetime of the command — readable by any local process
  via ps, whether or not it was ever echoed. Omitting the value makes security
  prompt for it instead. Corrected in the README, the ntucool-canvas skill, the
  wrapper's stderr hint, the server's instructions string, and the token-missing
  error message.

  The last two matter beyond documentation: they are compiled into the binary, so
  until this release the shipped server told users — and told the model, through
  instructions — to run the leaking form.