Merkle Tree Batch Verification (2D)

This is the 2D counterpart to the 3D Merkle tree scene: the identical batch-ledger model, hashed with a genuine FNV-1a mix across 4, 8 or 16 drug-batch records, drawn as a flat interactive tree diagram instead of a rendered cube grid. Tamper with any one batch and watch the avalanche effect pulse up the ancestor chain while every untouched node stays put; toggle the Merkle proof view to see how a verifier confirms a single batch's authenticity by checking just log₂(n) sibling hashes instead of re-hashing the entire ledger.