nested-prompts
Scans prompt subdirectories and registers them as /dir:name
commands. A file at prompts/command/new.md becomes /command:new.
Files starting with _ are skipped (templates, internal files).
Frontmatter in the markdown files controls display name, description, and argument handling.
Why it matters: As your prompt library grows, flat namespaces
become unwieldy. Subdirectory-based commands give you natural
grouping — /review:security, /generate:test, /refactor:types
— without manually registering each one.