Entry point. The off-chain executor builds a tx that invokes this once.
user: signer and flash-loan from. Repay is pulled from this account.receiver: the FlashArbReceiver contract that will run exec_op.blend_pool: Blend V2 pool address.amount: USDC notional to flash-borrow.params: trade config forwarded to Receiver.fn execute_arb(
env: soroban_sdk::Env,
user: soroban_sdk::Address,
receiver: soroban_sdk::Address,
blend_pool: soroban_sdk::Address,
amount: i128,
params: ArbParams,
)