Crypto market-wide derivatives snapshot: funding rate, open interest, mark price, and 24h volume for all 16 perpetual fu

Crypto market-wide derivatives snapshot: funding rate, open interest, mark price, and 24h volume for all 16 perpetual futures markets (BTC/ETH/SOL/BNB/XRP/DOGE/ADA/AVAX/LINK/DOT/LTC/TRX/BCH/ATOM/NEAR/APT). One call replaces 16 separate signals calls. Includes per-asset data freshness. Real-time from Kronos market_signals. Pay-per-call via x402.