rzv CLI 0.18.0: sign-in profiles

rzv 0.18.0 adds sign-in profiles and a default workspace setting.

• rzv login -p <profile> [-w <workspace>]Keeps one sign-in per profile, so signing in to a second account no longer replaces the first. -p works on every command, and RZV_PROFILE sets the profile for a shell.
• rzv profiles list|use|removeLists your local profiles, switches the active one, or removes a profile's local sign-in.
• RZV_WORKSPACE sets the default workspace, and --workspace accepts a workspace slug as well as an id.
• Downloads are on GitHub at https://github.com/Runzivo/rzv-cli/releases/latest. Release notes are on the same page.