CLI: De-emphasize server commands for deployer context

The single miren binary serves both deployer and server admin roles. Showing all commands in --help regardless of context is noisy for users who only deploy. Per team discussion, we want to keep a single binary but improve the experience for users who are only deploying.

The goal is to de-emphasize server/admin commands when you're in a deployer context, without hiding them to the point of confusing people. There are a few possible approaches - sectioning them off, graying them out, abbreviating them, collapsing them under a heading, etc. Part of tackling this ticket is figuring out the right strategy.

Key constraint: commands should always remain accessible and discoverable, just not equally prominent in every context.

Source: prospect feedback