dApp: hybrid POAP-like token system

[moul]

we want a system for hybrid minting tokens: on-chain or initialized off-chain, then minted on-chain.

use case: onboarding newcomers with a code + instructions, giving them time to create an account, use a faucet, and claim the token later.

let's discuss specs before implementation, focusing on the hybrid contract-oracle-web2 approach to balance flexibility and decentralization.