Add pre-trade market state verification to StockTradingEnv

Hi,

I saw FinRL and noticed StockTradingEnv uses datetime for scheduling but doesn't verify whether the exchange is actually open at execution time. That's the gap that causes silent failures when agents trade into closed markets or hit DST transitions.

I've been building Headless Oracle — a signed market oracle for AI agents. Before your agent executes, it fetches an Ed25519-signed attestation that the market is open. 60-second TTL, 28 exchanges.

import requests

r = requests.get('https://headlessoracle.com/v5/demo?mic=XNYS')
receipt = r.json()

if receipt['status'] != 'OPEN':
raise Exception(f"Market not open: {receipt['status']}")

Free to try (no key needed for /v5/demo). pypi.org/project/headless-oracle has LangChain and CrewAI tools built in.

Would you be open to adding a pre-trade market gate to the RL environment? Happy to write it.

— Mike (headlessoracle.com)