[codex] Pass proxy environment to CCXT loader

[ruok808]

Summary

• Read conventional proxy environment variables when constructing the CCXT exchange client.
• Pass the resulting proxies config to CCXT so public exchange data can be fetched from restricted networks.
• Add regression coverage for ALL_PROXY and for the no-proxy case.

Why

Requests-based loaders already inherit proxy environment variables, but CCXT does not reliably do so through this loader's current constructor path. In restricted network environments, Binance/OKX public market data can time out unless the proxy is passed explicitly to CCXT.

This change only uses environment variable names and never logs proxy values or credentials.

Tests

/Users/barry/Desktop/alevinno/src/vibe-trading-research/.venv/bin/python -m pytest agent/tests/test_ccxt_loader_proxy.py agent/tests/test_ccxt_loader_bounded.py agent/tests/test_get_market_data_unresolved.py -q

Result: 13 passed.

[warren618]

Thanks for the focused fix. I reviewed the diff and the approach looks reasonable to me.

I also verified the declared regression suite locally:

python -m pytest agent/tests/test_ccxt_loader_proxy.py agent/tests/test_ccxt_loader_bounded.py agent/tests/test_get_market_data_unresolved.py -q

Result: 13 passed.

One small process note: this PR is still marked as Draft, so we cannot treat it as ready to merge yet. When you are ready, please mark it as ready for review. After that I think this should be straightforward to merge.

Optional follow-up, not a blocker: it would be nice to add one more regression covering explicit HTTP_PROXY / HTTPS_PROXY taking precedence over ALL_PROXY, since the implementation already supports that behavior.