feat: aspens doc new — create custom skills from description

[mvoutov]

Summary

New command: aspens doc new <name> — lets users create custom skills by describing what they want, then Claude generates the skill file.

Flow

$ aspens doc new api-gateway

  What should this skill cover? Describe the domain, files, and patterns:
  > Our API gateway layer in src/gateway/ — handles rate limiting, 
  > auth middleware, request routing. Uses Express with custom middleware chain.

  Generating skill...

  + .claude/skills/api-gateway/skill.md

  Review and edit the skill, then run: aspens doc init --hooks-only

How it works

1. User provides skill name and a free-text description
2. aspens scans the repo (for context) and builds a prompt:
   • Repo structure + import graph
   • The user's description
   • Existing skills (so Claude doesn't duplicate)
   • Skill format spec (from skill-format.md partial)
3. Claude generates the skill.md with proper frontmatter, activation patterns, key files, etc.
4. User reviews/edits the generated skill
5. aspens doc init --hooks-only updates rules + hooks to include the new skill

Options

• --description "..." — provide description inline (skip interactive prompt)
• --dry-run — preview without writing
• --force — overwrite if skill already exists

Why this matters

Users often have domain knowledge that the scanner/discovery can't detect — internal conventions, specific business logic patterns, team workflows. This lets them seed a skill with their knowledge and let Claude fill in the structure.