China K12 Mathematics Knowledge Graph v1.0.0

First public release.\n\n- 1,327 mathematics topics across 18 books, 132 chapters, and 196 clusters\n- 1,204 prerequisite edges in a validated DAG\n- Offline Three.js/WebGL explorer\n- Deterministic layout, SHA-256 release manifest, and CI validation\n- Data and derived visualizations: CC BY-NC-SA 4.0 (non-commercial, share-alike)\n- Viewer and validation code: Apache License 2.0\n\nSee ATTRIBUTION.md for K12-KGraph and Marble contract attribution.