#556

fix(cli): drive dispatch and help from one command list

Openlahfirwants to merge intofrom
  1. Command names were copied by hand into several lists that drifted apart, so trust --help, proxy start --help, hosts sync --help, and prune --force --help ran the command, and PORTLESS=0 portless get backend ran backend as a shell command.
  2. One list of command names now drives dispatch, help, PORTLESS=0, and typo hints, so --help always prints help without running anything, and portless lsit suggests portless list.
  3. Builds on #546.