refactor:优化汇率编辑功能

- 移除货币名称选择框，改为只读输入框

src/views/managerecharge/rate.vue

@@ -94,7 +94,7 @@ const checkFreeGoldRadio = function (rule, value, callback) {
 }
 // 定义表单验证规则
 const rules = reactive({
-  rateName: [{required: true, message: '请选择货币名称', trigger: 'blur'}],
+  // rateName: [{required: true, message: '请选择货币名称', trigger: 'blur'}],
   num: [{validator: checkFreeGoldRadio, trigger: 'blur'}],
 })
 
@@ -426,18 +426,11 @@ onMounted(async function () {
           status-icon
       >
         <el-form-item prop="rateName" label="货币名称:">
-          <el-select
+          <el-input
               v-model="rateEdit.rateName"
-              placeholder="请选择"
+              disabled
               style="width: 240px"
-          >
-            <el-option
-                v-for="item in rateNames"
-                :key="item.value"
-                :label="item.label"
-                :value="item.value"
-            />
-          </el-select>
+          />
         </el-form-item>
 
         <el-form-item prop="num" label="汇率:">