Remove USDC product path; CoinOX is coin-margined only.

Drop USDC open/quote/swap APIs and env knobs; retarget hedge/settings copy to USDT/coin.

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

lib/common/static/hedge_plan.js

@@ -694,16 +694,16 @@
     }
     const line =
       label +
-      " · 交易 USDC " +
-      fmt(acct.trading_usdc, 2) +
-      " · 资金 USDC " +
-      fmt(acct.funding_usdc, 2);
+      " · 交易 USDT " +
+      fmt(acct.trading_usdt != null ? acct.trading_usdt : acct.trading_usdc, 2) +
+      " · 资金 USDT " +
+      fmt(acct.funding_usdt != null ? acct.funding_usdt : acct.funding_usdc, 2);
     const el = $("hp-opt-bal-line");
     if (el) el.textContent = line;
     const fundEl = $("hp-oo-funding-usdc");
     const tradeEl = $("hp-oo-trading-usdc");
-    if (fundEl) fundEl.textContent = fmt(acct.funding_usdc, 2);
-    if (tradeEl) tradeEl.textContent = fmt(acct.trading_usdc, 2);
+    if (fundEl) fundEl.textContent = fmt(acct.funding_usdt != null ? acct.funding_usdt : acct.funding_usdc, 2);
+    if (tradeEl) tradeEl.textContent = fmt(acct.trading_usdt != null ? acct.trading_usdt : acct.trading_usdc, 2);
     autoFillOoSheets();
   }
 
@@ -730,7 +730,7 @@
       const d = await apiJson("/api/options/transfer", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ ccy: "USDC", from: from, to: to, amount: amount }),
+        body: JSON.stringify({ ccy: "USDT", from: from, to: to, amount: amount }),
       });
       if (!d.ok) {
         setOoXferMsg(d.msg || "划转失败", "err");
@@ -1312,7 +1312,7 @@
     const ct = Number(state.selected.ct_mult || 0.01);
     const ask = Number(state.selected.ask || 0);
     const prem = ask * sheets * ct;
-    line.textContent = "预估权利金 ≈ " + fmt(prem, 4) + " USDC(期权账户)";
+    line.textContent = "预估权利金 ≈ " + fmt(prem, 4) + " 币(币本位)";
   }
 
   function buildStraddleRows(contracts) {
@@ -1561,7 +1561,7 @@
       fmt(b, 4) +
       " ≈ " +
       fmt(a + b, 4) +
-      " USDC";
+      " 币";
   }
 
   function legPayload(c, sheets) {
@@ -2051,7 +2051,7 @@
         }
         const amt = Math.floor(max * 100) / 100;
         const label = dir === "trading_to_funding" ? "交易 → 资金" : "资金 → 交易";
-        if (!window.confirm("确认全部划转?\n方向:" + label + "\n数量:" + amt + " USDC")) return;
+        if (!window.confirm("确认全部划转?\n方向:" + label + "\n数量:" + amt + " USDT")) return;
         const amtEl = $("hp-oo-xfer-amount");
         if (amtEl) {
           amtEl.removeAttribute("readonly");
@@ -2435,7 +2435,7 @@
       html +=
         "<div><span class=\"muted\">权利金合计</span> " +
         fmt(p.premium_total, 4) +
-        " USDC</div>";
+        " 币</div>";
       html +=
         "<div><span class=\"muted\">合约摘要</span> <code>" +
         (d.contracts_summary || "—") +