Add SIM/LIVE switch with API keys saved to .env and OKX live executor.

Enable settings UI for mode/keys, gate strategy start when LIVE is not ready, and stop PM2 from forcing MODE=SIM.

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

frontend/src/pages/Plan.tsx

@@ -132,10 +132,13 @@ export default function PlanPage() {
     <div>
       <h2 style={{ marginTop: 0 }}>自动对冲计划</h2>
       <p style={{ color: "var(--muted)", marginTop: -8 }}>
-        SIM 本地撮合 · 行情{" "}
+        {plan?.mode === "LIVE" ? "LIVE 实盘下单" : "SIM 本地撮合"} · 行情{" "}
         {(snap?.exchange || "okx").toUpperCase()}
         {snap?.perp_inst_id ? ` · ${snap.perp_inst_id}` : ""} ·
         目标平仓(双腿/远虚只平永续) · 未达标则到期结算
+        {plan?.mode === "LIVE" && plan.live_ready === false
+          ? ` · 未就绪: ${plan.live_ready_reason || "请配置 API"}`
+          : ""}
       </p>
       {err ? <div className="err">{err}</div> : null}
 
@@ -143,7 +146,16 @@ export default function PlanPage() {
         <button
           className="btn"
           type="button"
-          disabled={!!busy || plan?.running}
+          disabled={
+            !!busy ||
+            plan?.running ||
+            (plan?.mode === "LIVE" && plan.live_ready === false)
+          }
+          title={
+            plan?.mode === "LIVE" && plan.live_ready === false
+              ? plan.live_ready_reason || "LIVE 未就绪"
+              : undefined
+          }
           onClick={() => act("/api/plan/start", "start")}
         >
           启动策略
@@ -159,7 +171,9 @@ export default function PlanPage() {
         <button
           className="btn ghost"
           type="button"
-          disabled={!!busy}
+          disabled={
+            !!busy || (plan?.mode === "LIVE" && plan.live_ready === false)
+          }
           onClick={() => act("/api/sim/open-group", "open")}
         >
           手动开一组