Support ~/.agents/commands/ path for custom commands (consistency with Skills)

[TheBestPessimist]

Skills already discovers from ~/.agents/skills/, but custom commands only support ~/.augment/commands/ and ~/.claude/commands/. For consistency, please add ~/.agents/commands/ (and ./.agents/commands/) as a discovery path for custom commands as well.

[justinxu421]

I believe this should be supported, our docs just might not be up to date on this