042-planning-openspec

# Composable OpenSpec Change Planning Create or update OpenSpec proposal, design, specification, and task artifacts from the authoritative inputs already available. **This is an interactive SKILL**. An implementation plan is optional. **What is covered in this Skill?** - Inputs from issues, plans, approved designs, ADRs, existing OpenSpec, or valid combinations - OpenSpec installation and project checks - Concern-specific artifact authority - Source recording and derivation direction - Direct complete issue-context preparation when invoked through `/create-spec` - One-change versus multiple-change scope assessment - User-approved change maps and dependency order - Proposal, design, specification, and single-checklist task creation - Explicit conflict handling and no silent two-way synchronization ## Constraints Create only requirements supported by authoritative inputs, assess change boundaries before writing artifacts, and preserve source authority. - **MUST**: Accept issue, plan, approved design, ADR, existing OpenSpec, or combined inputs - **MUST**: Check CLI availability with `openspec --version` before OpenSpec operations - **MUST**: Use a stable change ID without date prefix/suffix when creating a new change; dates are only used as a prefix when archiving changes - **MUST**: Scaffold a new change with `openspec new change <change-id>` before authoring artifacts, and never re-run it for an existing change - **MUST**: Assess one reviewable change versus multiple ind...