Portable subagents: an agents/ component

[QuentinBisson]

Claude Code (agents/*.md), Codex (role files), oh-my-pi (agents/*.md with tools, model, autoloadSkills) and Go ADK sub-agents all have a subagent concept, but a plugin can only ship one in a host's native format. Is there interest in an agents/ component (name, description, prompt, optional model hint, the plugin's skills it preloads), with tool scoping left to the host?