Allow risk-based 永期 exits via premium multiple as well as base×k.

Settings UI picks 基数 or 权利金×n; sizing preview and control monitor follow.

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

frontend/src/pages/Plan.tsx

@@ -216,7 +216,11 @@ export default function PlanPage() {
         }${fmt(ooRatio, 1)}）`
       : `净盈≥预算×${fmt(ooRatio, 1)}（达标只平盈利腿）`
     : exitMode === "premium_multiple"
-      ? `权利金×${fmt(plan?.premium_exit_multiple ?? 1, 2)}`
+      ? riskBased
+        ? exitTarget != null
+          ? `${riskLocked ? "锁定 " : ""}净盈≥${fmt(exitTarget)} U（权利金×${fmt(plan?.premium_exit_multiple ?? 1, 2)}）`
+          : `权利金×${fmt(plan?.premium_exit_multiple ?? 1, 2)}（开仓后锁定）`
+        : `权利金×${fmt(plan?.premium_exit_multiple ?? 1, 2)}`
       : riskBased
         ? exitTarget != null
           ? `${riskLocked ? "锁定 " : "固定 "}${fmt(exitTarget)} U（基数${fmt(plan?.risk_exit_unit ?? 15)}）`