Specifies the L1-L4 ingestion resolution ladder (encrypted local cache, Open Food Facts branded/barcode lookups, USDA FoodData Central fallback for whole/unbranded foods, manual entry), the FoodProduct domain model and FoodProductsTable schema, the OFF/USDA nutrient mapping table, and network resiliency rules (mandatory custom User-Agent, 4-second circuit timeout with automatic fallback, write-through SQLCipher caching).