{"L1_core": {"domain": "general", "category": "accessory", "entity_type": "product"}, "L2_general": {"functions": ["mounting", "connection", "protection", "extension", "aesthetic"], "management": ["independent_SKU", "separate_or_kit", "coordinated_obsolescence"], "documentation": ["compatibility_list", "installation_instructions", "specifications"]}, "L5_metadata": {"updated": "2026-01-02", "version": "2.0"}}