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/home/components/FacilityLocationCard/index.vue

@@ -4,7 +4,7 @@
 
     <div class="facility-location-card__body px-24 pb-24">
       <div class="facility-location-card__title-row flex flex-items-center">
-        <div class="facility-location-card__badge color-2563EB bg-EFF6FF font-size-12 font-900">
+        <div class="facility-location-card__badge color-2563EB bg-EFF6FF text-[12px] font-900">
           {{ type.text }}
         </div>
         <div class="facility-location-card__title color-1E293B font-size-18 font-900 ellipsis-1">
@@ -12,7 +12,7 @@
         </div>
       </div>
 
-      <div class="facility-location-card__distance flex flex-items-center color-94A3B8 font-size-14 font-900">
+      <div class="facility-location-card__distance flex flex-items-center color-94A3B8 text-[14px] font-900">
         <span class="facility-location-card__distance-icon">{{ distance.icon }}</span>
         <span>{{ distance.text }}</span>
       </div>