Ingest external plans with conflict detection

Import external plan files with conflict detection

Ingesting external planning artifacts without overwriting existing project decisions, using conflict detection as a safety gate.

• · --from <filepath> pointing to external plan (ADR, PRD, SPEC, RFC, or free-form markdown)

• · GSD PLAN.md for new phase or phase extension
• · Conflict report against existing PROJECT.md decisions
• · Validation via gsd-plan-checker

• · import.md workflow
• · doc-conflict-engine.md
• · gate-prompts.md
• · gsd-plan-checker

• · External plan file is readable markdown or structured text
• · .planning/PROJECT.md exists (if merging into existing project)

• · Conflicts detected with PROJECT.md decisions → BLOCKER gate prevents write
• · --from path not found → error reported
• · External plan format unrecognized → generic parsing attempted

• · Conflict detection via shared engine (gate-prompts.md)
• · BLOCKER safety rule: no destination write if unresolved contradictions
• · Validation via gsd-plan-checker before finalizing