/goal usage text omits implemented control subcommands

What happened?

The TUI usage text for /goal currently says only:

Usage: /goal <objective>

That usage appears when parsing fails and when no goal is currently set. However, the slash-command implementation also supports control forms such as:

• /goal clear
• /goal edit
• /goal pause
• /goal resume

The goal menu already advertises these control commands depending on goal status.

Expected behavior

The /goal usage/help text should mention the supported control forms, or otherwise point users toward the goal menu commands, so users can discover the implemented lifecycle actions without already having a goal summary open.

Additional context

I searched open issues and PRs for terms including /goal, clear, pause, resume, edit, and usage text, and did not find an existing open item that appears to cover this TUI help mismatch.