fix(后台充值商品): 列表为空时重置表单

- 抽出 DEFAULT_RECHARGE_PRODUCT_FORM 并让新建表单初始化与 resetForm 共用。
- 过滤后没有泥点商品时调用 resetForm，避免表单残留上一次选中或已删除商品的旧值被误保存。

apps/admin-web/src/pages/AdminRechargeProductPage.tsx

@@ -32,6 +32,19 @@ interface AdminRechargeProductPageProps {
   onResultChange: (result: ProfileRechargeProductConfigAdminResponse) => void;
 }
 
+/** 新建泥点商品时的表单默认值；列表为空时回填它，避免残留上一次选中项。 */
+const DEFAULT_RECHARGE_PRODUCT_FORM = {
+  productId: 'points_60',
+  title: '60泥点',
+  priceCents: '600',
+  pointsAmount: '60',
+  bonusPoints: '0',
+  badgeLabel: '',
+  description: '60泥点',
+  enabled: true,
+  sortOrder: '0',
+};
+
 /**
  * 泥点充值商品。
  *
@@ -47,15 +60,29 @@ export function AdminRechargeProductPage({
   const [entries, setEntries] = useState<
     ProfileRechargeProductConfigAdminResponse[]
   >([]);
-  const [productId, setProductId] = useState('points_60');
-  const [title, setTitle] = useState('60泥点');
-  const [priceCents, setPriceCents] = useState('600');
-  const [pointsAmount, setPointsAmount] = useState('60');
-  const [bonusPoints, setBonusPoints] = useState('0');
-  const [badgeLabel, setBadgeLabel] = useState('');
-  const [description, setDescription] = useState('60泥点');
-  const [enabled, setEnabled] = useState(true);
-  const [sortOrder, setSortOrder] = useState('0');
+  const [productId, setProductId] = useState(
+    DEFAULT_RECHARGE_PRODUCT_FORM.productId,
+  );
+  const [title, setTitle] = useState(DEFAULT_RECHARGE_PRODUCT_FORM.title);
+  const [priceCents, setPriceCents] = useState(
+    DEFAULT_RECHARGE_PRODUCT_FORM.priceCents,
+  );
+  const [pointsAmount, setPointsAmount] = useState(
+    DEFAULT_RECHARGE_PRODUCT_FORM.pointsAmount,
+  );
+  const [bonusPoints, setBonusPoints] = useState(
+    DEFAULT_RECHARGE_PRODUCT_FORM.bonusPoints,
+  );
+  const [badgeLabel, setBadgeLabel] = useState(
+    DEFAULT_RECHARGE_PRODUCT_FORM.badgeLabel,
+  );
+  const [description, setDescription] = useState(
+    DEFAULT_RECHARGE_PRODUCT_FORM.description,
+  );
+  const [enabled, setEnabled] = useState(DEFAULT_RECHARGE_PRODUCT_FORM.enabled);
+  const [sortOrder, setSortOrder] = useState(
+    DEFAULT_RECHARGE_PRODUCT_FORM.sortOrder,
+  );
   const [isLoading, setIsLoading] = useState(false);
   const [isSaving, setIsSaving] = useState(false);
   const [listErrorMessage, setListErrorMessage] = useState('');
@@ -80,6 +107,9 @@ export function AdminRechargeProductPage({
       const firstEntry = sortedEntries[0];
       if (firstEntry) {
         fillForm(firstEntry);
+      } else {
+        // 中文注释：列表为空时回填新建默认值，避免表单残留已删除商品的旧值被误保存。
+        resetForm();
       }
     } catch (error: unknown) {
       handlePageError(error, onUnauthorized, setListErrorMessage);
@@ -149,6 +179,18 @@ export function AdminRechargeProductPage({
     setSortOrder(String(entry.sortOrder));
   }
 
+  function resetForm() {
+    setProductId(DEFAULT_RECHARGE_PRODUCT_FORM.productId);
+    setTitle(DEFAULT_RECHARGE_PRODUCT_FORM.title);
+    setPriceCents(DEFAULT_RECHARGE_PRODUCT_FORM.priceCents);
+    setPointsAmount(DEFAULT_RECHARGE_PRODUCT_FORM.pointsAmount);
+    setBonusPoints(DEFAULT_RECHARGE_PRODUCT_FORM.bonusPoints);
+    setBadgeLabel(DEFAULT_RECHARGE_PRODUCT_FORM.badgeLabel);
+    setDescription(DEFAULT_RECHARGE_PRODUCT_FORM.description);
+    setEnabled(DEFAULT_RECHARGE_PRODUCT_FORM.enabled);
+    setSortOrder(DEFAULT_RECHARGE_PRODUCT_FORM.sortOrder);
+  }
+
   return (
     <AdminPage wide>
       <AdminPageHeading