📄️Trace Lot Genealogy
Returns a genealogy tree for a batch/lot. `batch_number` is required; `product_id` is optional and auto-resolved from the batch number when it uniquely identifies a FIFO layer. When the same batch number is used across multiple products, the API responds 409 with a `candidates` array so a UI can prompt for product disambiguation. Direction `backward` traces from finished good back to raw material inputs (recall use case); `forward` traces from raw material to all downstream produced lots (recall impact analysis).