Function assemble_plugin 

pub fn assemble_plugin(
    skill_dirs: &[&Path],
    opts: &AssembleOptions,
) -> Result<AssembleResult>

Assemble skills into a plugin directory.

Creates the output directory structure:

<output_dir>/
├── plugin.json
├── skills/
│   ├── <skill-1>/
│   │   └── SKILL.md
│   └── <skill-2>/
│       └── SKILL.md

Errors

Returns an error if:

• No valid skills are found in the input directories
• The output directory cannot be created
• Skill files cannot be read or copied