Arbitrum Bot Hides Ops in Calldata, Not Selectors

Arbitrum bot hides ops in calldata, not selectors. 2,797 txns show 15 distinct 4-byte headers; two values cover 77.6%. Contract has only 2 real selectors: 0x8e16402f (owner sweep) and 0x91dd7346 (Uniswap v4 callback). First byte becomes hop_count; 39-byte chunks encode route. Exploiters bypass dispatch tables.