⚡ USDA Foundation Foods Batch Processor

Upload CSV files from the Foundation Foods download at fdc.nal.usda.gov/download-datasets.
Joins locally — no API calls, no rate limits — averages all samples of the same food description, then pushes clean entries to Firestore master_foods.
Required: food.csv + food_nutrient.csv + nutrient.csv  |  Optional: food_portion.csv (adds cup measurements)