Add Gitea CI workflow for registry validation, reuse-surface overlaps and
catalog commands, generated catalog artifacts, and documentation updates
closing gap analysis priorities 9-11.
Align INTENT.md with delivered layout, add CapabilityRegistryConcept guide,
extend schema with promotion_history, ship reuse-surface validate/query/export
CLI, register three more helix_forge capabilities, and refresh SCOPE and gap
analysis to reflect A3 tooling and D5/A3/C4/R2 self-assessment.
