createEvmVerifier previously scanned every Transfer event on the settlement
token with no address filter. Verified live against Arc Testnet: a 5000-block
window over a busy token contract exceeded the RPC's max-results cap
("query exceeds max results 20000"). Fix: pass the agent set as an OR-matched
indexed 'from' topic, so the query is scoped server-side. Re-verified against
the same live window post-fix — correct result, no cap error.