Fetch option Delta from OKX opt-summary into the chain.

market/tickers has no greeks; merge public/opt-summary delta/gamma when building the strike table.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/exchange/okx_public_http_lib.py

@@ -165,3 +165,20 @@ def fetch_option_tickers_public(inst_family: str) -> dict[str, dict[str, Any]]:
         if isinstance(r, dict) and r.get("instId"):
             out[str(r["instId"])] = r
     return out
+
+
+def fetch_option_summary_public(inst_family: str) -> dict[str, dict[str, Any]]:
+    """期权摘要(含 delta/gamma 等);market/tickers 不含希腊字母."""
+    family = str(inst_family or "").strip()
+    if not family:
+        return {}
+    payload = okx_public_get(
+        "/api/v5/public/opt-summary",
+        {"instFamily": family},
+        timeout_sec=12.0,
+    )
+    out: dict[str, dict[str, Any]] = {}
+    for r in payload.get("data") or []:
+        if isinstance(r, dict) and r.get("instId"):
+            out[str(r["instId"])] = r
+    return out