Pick a claim variant
v1 had one way to authorise a claim: an admin signed an EIP-712 message per recipient. v2 has two, and the choice is made at create time because each variant is a different implementation contract.
**ECDSA** keeps the v1 model. A holder of `SIGNER_ROLE` signs an authorisation naming the recipient, the encrypted amount, a `dedupId` and a `deadline`. Good when allocations are decided as you go, or when a backend already holds a signing key.
**Merkle** publishes one root covering the whole roster. Nobody signs per recipient; a claim proves inclusion instead. Good when the roster is known up front, and it is the only variant that supports relayed claims.
Aria has a fixed list of 500 contributors, so she takes the Merkle path. The chapters that follow build it; "The ECDSA path, for contrast" shows the other shape.