fix: bug

hooks/use-pricing.ts

@@ -261,8 +261,15 @@ export function usePricing() {
       return null;
     }
 
+    // 检查 pricing data 是否加载完成
     if (!stripePricingData?.pricing_table_items?.[0]?.metered_price_id) {
-      Alert.alert('Error', 'Pricing data not available');
+      Alert.alert('Error', 'Pricing data not available. Please try again later.');
+      return null;
+    }
+
+    // 检查用户是否有 metered subscription
+    if (!meteredSubscriptions || meteredSubscriptions.length === 0 || !meteredSubscriptions[0]?.priceId) {
+      Alert.alert('Error', 'No active metered subscription found. Please contact support.');
       return null;
     }