Read a binding batch with wallet authorization

Wallet EIP-191 message: Mobius venue binding v1\ndomain=<BINDING_AUTH_DOMAIN or mobius-api>\naction=<prepare or read>\npayload=<canonical JSON>, with actual newline characters and no trailing newline. Canonical JSON recursively sorts object keys, preserves array order, and contains no whitespace. Lowercase the owner. Sign the exact message; ECDSA wallets only. Read payload is {owner,bindingId,expiresAt}. Pass its personal_sign signature using the wallet headers. A different authenticated wallet receives 404. This GET only reads persisted state. A read signature can be reused until its short expiry for the same binding. Batch results retain successful venues when others fail/expire. confirming may persist after expiry for uncertain external outcomes; continue polling or reconcile operationally.