feat(红包功能): 优化输入验证逻辑，允许红包抵扣后金额为0

src/views/consume/gold/addCoinConsume.vue

@@ -77,6 +77,19 @@ const rules = reactive({
     { required: true, message: t('elmessage.noEmptySumGold'), trigger: "blur" },
     {
       validator: (rule, value, callback) => {
+        // 如果使用了红包，且红包总额抵扣完了原价，允许为0
+        if (addConsume.value.redMoney === 1) {
+          const price = Number(addConsume.value.price || 0)
+          const redAmount = totalRedAmount.value
+          if (redAmount >= price) {
+            // 如果红包抵扣完了，允许0
+            if (parseFloat(value) === 0 || value === 0) {
+              callback();
+              return;
+            }
+          }
+        }
+        
         // 允许0开头的小数（如0.1）但不允许单独的0
         const isValid = /^(0\.\d{1,2})|([1-9]\d*(\.\d{1,2})?)$/.test(value);
 
@@ -561,7 +574,7 @@ watch(
   () => addConsume.value.sumGold,
   (newValue) => {
     const parsedNewValue = parseFloat(newValue);
-    if (!isNaN(parsedNewValue) && parsedNewValue > 0) {
+    if (!isNaN(parsedNewValue) && parsedNewValue >= 0) {
       const { free, permanent, task } = calculateCoins(parsedNewValue);
       addConsume.value.freeGold = free;
       addConsume.value.permanentGold = permanent;