Call when an agent needs the latest SEC EDGAR filings for a ticker or CIK, with an optional form filter, a limit, and filing URLs. The ticker map is cached. The call sends SEC's required User-Agent. Recent submissions only. Send JSON {"ticker":"AAPL","form":"10-K","limit":1}. Exact $0.003 USDC on Base. Try unpaid POST /v1/sandbox/sec-edgar-filings first.