When a Claude plugin skill's SKILL.md frontmatter uses a display-style
name (e.g. `name: Understand Anything`), the synthesized slash command
inherited that text. `expandSlashCommand` splits the command at the
first whitespace, so `/understand` never resolved and the multi-word
form could not expand either.
Use `path.basename(path.dirname(skill.path))` so the slash command
always matches the documented `skills/<name>/SKILL.md` → `/<name>`
contract while the frontmatter still drives the description/body.
Fixes#2415
roboomp
fde233278c