What miner metadata does Kaspa store in coinbase payload commitments?

Kaspa's coinbase payloads are the conventional place where miners signal extra metadata — such as which mining software or pool produced a block. Because Kaspa is a blockDAG, many miners' blocks can appear in each block's mergeset. KIP-0021 commits each payload hash together with the block's own hash and its blue_work value (a measure of accumulated proof-of-work behind that block), creating a tamper-evident record that ties a miner's identity data to a specific position in the DAG. This matters because Layer 2 applications built on Kaspa can use these committed payloads to audit miner activity or verify pool participation claims across the entire block graph — not just on the main selected chain.