Fix(云灵AI):[#5368]未选择选项卡的情况下点击“下一步”，缺少必填校验

aiChat/mixins/chatMixinsV2.js

@@ -784,6 +784,25 @@ export const chatMixinsV2 = {
       }
     },
     nextGiftStep() {
+      const currentStep = this.giftBuyOptions[this.currentGiftStepIndex]
+      let hasSelection = false
+      
+      // 校验是否已选择
+      if (currentStep.type === 'option_card') {
+        const selectedIds = this.giftSelections[currentStep.id] || []
+        hasSelection = selectedIds.length > 0
+      } else if (currentStep.type === 'price_input') {
+        hasSelection = !!this.giftBudget
+      }
+
+      if (!hasSelection) {
+        uni.showToast({
+          title: '请完善信息后再点击下一步',
+          icon: 'none'
+        })
+        return
+      }
+
       if (this.currentGiftStepIndex < this.giftBuyOptions.length - 1) {
         this.currentGiftStepIndex++
       } else {