Merkle Proof Tamper Detection

This simulator builds a real SHA-256 Merkle tree in the browser — the same cryptographic structure blockchains use to let light clients verify a single transaction against one trusted root hash. Select a leaf, tamper its underlying data, and run Verify Proof to watch the mismatch propagate node-by-node from the leaf all the way to the root, exactly as it would when a node rejects a forged inclusion proof. Rebuild the tree honestly to see the alternative: a legitimate data change publishes a brand-new trusted root instead of trying to reuse stale hashes.