plan init and plan create Commands

Summary

Scaffolding commands that create plan directories and template files. init sets up the full plan structure in a new project. create scaffolds individual plan items from templates. Neither command needs the scanner — they only write files.

Acceptance Criteria

• plan init creates plan/work/, plan/spec/, plan/decision/ directories
• plan init generates example files (work item, decision, spec) and starter index.md
• plan init appends workflow section to CLAUDE.md (or creates one) including next/update/status commands
• plan create work --id WORK-XXX --title "..." scaffolds a work item from template
• plan create supports all 5 types: work, bug, decision, spec, milestone
• Templates include all required sections per plan/CLAUDE.md structure
• Tests for directory creation, file generation, and template rendering

Approach

Templates live in runes/plan/src/templates/ as string constants (not separate files). Each template is a function that accepts attributes and returns a Markdoc string. init calls create internally for its example files.

Dependencies

• CLI Plugin Discovery Architecture (plugin architecture — so commands can be registered)

References

• Plan CLI (Plan CLI)
• plan/CLAUDE.md (required content structure)