Audit artifact_poc.md against existing codebase to mark what already
exists vs what's genuinely new:
- Slice 4 CLI table: Added Status column (NEW/EXISTS)
- Added "Existing CLI commands" section listing what's not in scope
- Updated Implementation Order Slice 4 with explicit new vs existing
- Summary table: Updated status + added "What already exists" section
Key finding: The document was already well-simplified. Only truly new
functionality (createChange, validateChangeName, InstructionLoader,
artifact graph CLI commands) is proposed.
Add internal documentation for the artifact-based approach to OpenSpec
core. This document outlines design decisions, terminology, and the
philosophy behind treating dependencies as enablers rather than gates.