osovv/grace-marketplace/grace-explainer

<skill> <core_model> GRACE 4 uses .grace as the durable project model:

• .grace/context stores requirements, technology, principles, deployment, and UX constraints.
• .grace/graph stores graph indexes and routed graph documents with GD-*, M-*, and DF-* tags.
• .grace/verification stores verification indexes and routed V-M-* entries.
• .grace/changes stores active and archived C-* change bundles with GraceChangeSpec, optional non-normative design context, and GraceChangePlan.

</core_model>

<workflow>

1. grace-init creates the .grace skeleton.
2. grace-spec creates an active change spec and waits for approval.
3. grace-plan creates assertions, scopes, and T-* implementation tasks.
4. grace-execute runs sequential or parallel-safe mode from the approved plan.
5. grace lint and grace status provide validation and health evidence.
6. Existing GRACE 3 projects use grace-migrate; the CLI validates the result but does not convert legacy docs directly.

</workflow> </skill>