Controller method name → Soroban Symbol.
Optionalpredecessorpredecessor: BytesN<32> — defaults to the 32-zero-byte value used for
every op in this system. Override only if a non-zero predecessor is used.
salt: BytesN<32> — the same salt used at propose time.
Controller (or other) contract the scheduled op targets.
The controller-call args, each a base64 ScVal XDR string. These must be the SAME ScVals the matching proposal scheduled (the timelock hashes them into the op id), in the controller method's arg order. Reconstructed via
xdr.ScVal.fromXDR(s, 'base64').