Show open time and hold duration on position cards.

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

frontend/src/api/client.ts

@@ -238,6 +238,7 @@ export type PlanState = {
   position: {
     has_position: boolean;
     group_id?: string;
+    open_at_ms?: number | null;
     perp_side?: string;
     option_side?: string;
     perp_inst_id?: string;

frontend/src/pages/Plan.tsx

@@ -41,6 +41,33 @@ function formatCountdown(msLeft: number): string {
   return `${m}分 ${String(sec).padStart(2, "0")}秒`;
 }
 
+/** 上海时区开仓时间 */
+function fmtOpenTime(ms: number | null | undefined) {
+  if (ms == null || !Number.isFinite(ms) || ms <= 0) return "—";
+  return new Date(ms).toLocaleString("zh-CN", {
+    timeZone: "Asia/Shanghai",
+    hour12: false,
+    month: "2-digit",
+    day: "2-digit",
+    hour: "2-digit",
+    minute: "2-digit",
+    second: "2-digit",
+  });
+}
+
+/** 持仓时长（实时） */
+function fmtHoldDuration(openAtMs: number | null | undefined, now: number) {
+  if (openAtMs == null || !Number.isFinite(openAtMs) || openAtMs <= 0) return "—";
+  const ms = Math.max(0, now - openAtMs);
+  const totalSec = Math.floor(ms / 1000);
+  const h = Math.floor(totalSec / 3600);
+  const m = Math.floor((totalSec % 3600) / 60);
+  const s = totalSec % 60;
+  if (h > 0) return `${h}时${m}分${s}秒`;
+  if (m > 0) return `${m}分${s}秒`;
+  return `${s}秒`;
+}
+
 const PHASE_ZH: Record<string, string> = {
   idle: "空闲",
   wait_signal: "等待信号",
@@ -132,6 +159,9 @@ export default function PlanPage() {
     plan?.mode === "LIVE"
       ? `实盘·${(snap?.exchange || "okx").toUpperCase()}`
       : "模拟盘";
+  const openAtMs = pos?.open_at_ms ?? null;
+  const openTimeLabel = fmtOpenTime(openAtMs);
+  const holdDurationLabel = open ? fmtHoldDuration(openAtMs, nowMs) : "—";
 
   return (
     <div className="plan-page">
@@ -429,6 +459,14 @@ export default function PlanPage() {
                       <span className="pos-label">波动比例</span>
                       <span className="pos-value mono">{fmt(movePct, 2)}%</span>
                     </div>
+                    <div className="pos-cell">
+                      <span className="pos-label">开仓时间</span>
+                      <span className="pos-value mono">{openTimeLabel}</span>
+                    </div>
+                    <div className="pos-cell">
+                      <span className="pos-label">持仓时长</span>
+                      <span className="pos-value mono">{holdDurationLabel}</span>
+                    </div>
                   </div>
                 </div>
 
@@ -482,6 +520,14 @@ export default function PlanPage() {
                       <span className="pos-label">初始权利金</span>
                       <span className="pos-value mono">{fmt(pos?.initial_premium)}</span>
                     </div>
+                    <div className="pos-cell">
+                      <span className="pos-label">开仓时间</span>
+                      <span className="pos-value mono">{openTimeLabel}</span>
+                    </div>
+                    <div className="pos-cell">
+                      <span className="pos-label">持仓时长</span>
+                      <span className="pos-value mono">{holdDurationLabel}</span>
+                    </div>
                   </div>
                 </div>
               </>