feat: enhance user management and system optimization

New Features:
- Add bulk ban and email notification in user management
- Add CSV export for batch coupon generation
- Optimize subscription description template

Bug Fixes:
- Fix knowledge base pagination issue
- Fix permission group filtering in node management
- Fix unauthorized order placement for free subscription periods

app/Services/PlanService.php

@@ -75,16 +75,17 @@ class PlanService
         // 转换周期格式为新版格式
         $periodKey = self::getPeriodKey($period);
 
+
+        // 检查价格时使用新版格式
+        if (!isset($this->plan->prices[$periodKey]) || $this->plan->prices[$periodKey] === NULL) {
+            throw new ApiException(__('This payment period cannot be purchased, please choose another period'));
+        }
+
         if ($periodKey === Plan::PERIOD_RESET_TRAFFIC) {
             $this->validateResetTrafficPurchase($user);
             return;
         }
 
-        // 检查价格时使用新版格式
-        if (!isset($this->plan->prices[$periodKey])) {
-            throw new ApiException(__('This payment period cannot be purchased, please choose another period'));
-        }
-
         if ($user->plan_id !== $this->plan->id && !$this->hasCapacity($this->plan)) {
             throw new ApiException(__('Current product is sold out'));
         }