[NFR-6-04] Dry-run world & approval

[SamMRoberts]

ID: NFR-6-04\nType: NFR\nPhase: 6\nBaseline: true\n\nDescription\nStaging shard; approve/publish workflow; rollback.\n\nAcceptance Criteria\n- [ ] Implemented\n- [ ] Tests passing\n- [ ] Docs updated