style: migrate font-size classes to text-[size] syntax

Additionally update spacing utilities and refactor the OrderQrcode component:
- Switch popup implementation from uni-popup to van-popup
- Remove the deprecated SCSS stylesheet
- Clean up component template and script code

src/pages/booking/components/UserSection/index.vue

@@ -10,31 +10,20 @@
     </div>
 
     <div class="border-box pl-12 pr-12">
-      <div
-        class="border-box border-bottom pt-12 pb-12 flex flex-items-center"
-        v-for="(item, index) in userFormList"
-        :key="index"
-      >
-        <div class="font-size-14 font-500 color-525866 mr-12">住客姓名</div>
+      <div class="border-box border-bottom pt-12 pb-12 flex flex-items-center" v-for="(item, index) in userFormList"
+        :key="index">
+        <div class="text-[14px] font-500 color-525866 mr-12">住客姓名</div>
         <div class="right">
-          <input
-            class="border-box px-4 py-2 font-size-15 color-000 line-height-20"
-            v-model.trim="item.visitorName"
-            placeholder="请输入姓名"
-            maxlength="11"
-          />
+          <input class="border-box px-4 py-2 font-size-15 color-000 line-height-20" v-model.trim="item.visitorName"
+            placeholder="请输入姓名" maxlength="11" />
         </div>
       </div>
 
       <div class="flex flex-items-center border-box pt-12 pb-12">
-        <div class="font-size-14 font-500 color-525866 mr-12">联系手机</div>
+        <div class="text-[14px] font-500 color-525866 mr-12">联系手机</div>
         <div class="right">
-          <input
-            class="border-box px-4 py-2 font-size-15 color-000 line-height-20"
-            v-model.trim="userFormList[0].contactPhone"
-            placeholder="请输入联系手机"
-            maxlength="11"
-          />
+          <input class="border-box px-4 py-2 font-size-15 color-000 line-height-20"
+            v-model.trim="userFormList[0].contactPhone" placeholder="请输入联系手机" maxlength="11" />
         </div>
       </div>
     </div>