blockchain/Blockchain 101: Wallets, Keys, ChainsProject · Build a Toy Ledgerprojecthardmodule projectShip something real. Submit your work when you're done.BriefWrite a 100-line Python or JS script that represents a blockchain: append-only, hash-linked, validates on each insert.DeliverablesWorking code or on-chain artifact (tx hash, contract address, signature).Short README explaining what you built and how to verify.How we grade itRuns / verifies without hand-holding.Uses concepts from this module.Has a failure mode documented (what breaks and why).