[RFP] Privacy-Preserving Wrapped ERC-20 and Ether Bridge for LEZ

[fryorcraken]

Draft PR: logos-co/rfp#158

RFP-022, split out from #123 (originally "[RFP] Wrapped Eth & ERC-20").

Lock-and-mint bridge with unlinkability as a hard requirement: no signal other than amount, token, and timing may link an Ethereum deposit to the LEZ mint it funds, or a LEZ burn to the Ethereum release it triggers. Depends on RFP-021 (Trustless Ethereum State Attestation, tracked in #123).