Problem

NemoClaw has decent top-level help, but most commands do not support command-scoped --help. Users have to infer usage from the global help page, implementation details, or docs.

Scope

• Add --help support for all top-level commands such as onboard, deploy, start, stop, status, debug, uninstall, and setup-spark
• Add --help support for sandbox-scoped actions such as connect, status, logs, policy-add, policy-list, and destroy
• Standardize help output to include purpose, usage, options, examples, and related commands

Acceptance Criteria

• nemoclaw <command> --help exits 0 for every top-level command
• nemoclaw <sandbox> <action> --help exits 0 for every sandbox-scoped action
• Help text includes at least one example per command
• CLI tests cover all supported help entry points

Context

This came out of a CLI review against https://clig.dev/. It is the highest-value discoverability gap in the current CLI surface.