* fix(cli): run group subcommands in the lite shell and default to the logged-in gateway
Typing a command group alone in the lite shell printed 'Usage: lite lite',
the next subcommand was unknown, quoted arguments were split on spaces, and
a bare lite connected to localhost:4000 even after lite login to a gateway.
The shell now names the group in usage text, keeps the group as the prompt's
scope so its subcommands run next, accepts a leading 'lite', parses lines
with shlex, and a bare lite falls back to the server the stored lite login
credential was issued for before localhost:4000.
* refactor(cli): walk the shell's group path without recursion
* fix(cli): keep backslashes and compact JSON in the lite shell and pair the login server with its key
* fix(cli): keep the login server to the bare lite shell and accept lite options and = quoting at its prompt
* fix(cli): keep the shell's server for a lite options line and name the right login in the keychain notice
* fix(cli): keep compact JSON with a trailing = intact in the shell and pin options lines to the shell's server over LITELLM_PROXY_URL
