Add Apache Superset OpenAPI documentation reference to ROOT.md

.ai/ROOT.md

@@ -32,6 +32,7 @@ Use these for code generation (Style Transfer).
 ## 3. DOMAIN MAP (Modules)
 *   **Module Map:** `.ai/MODULE_MAP.md` -> `[DEF:Module_Map]`
 *   **Project Map:** `.ai/PROJECT_MAP.md` -> `[DEF:Project_Map]`
+*   **Apache Superset OpenAPI:** `.ai/openapi.json` -> `[DEF:Doc:Superset_OpenAPI]`
 *   **Backend Core:** `backend/src/core` -> `[DEF:Module:Backend_Core]`
 *   **Backend API:** `backend/src/api` -> `[DEF:Module:Backend_API]`
 *   **Frontend Lib:** `frontend/src/lib` -> `[DEF:Module:Frontend_Lib]`