refactor: remove custom font-weight scss and update class usages

Delete the standalone font-weight.scss utility file, remove its import from the main scss index, and update all existing references to the custom font-{weight} classes to use either built-in semantic font utilities or inline functional font weight classes matching the project's utility-first styling pattern.

src/pages/goods/album/index.vue

@@ -2,7 +2,7 @@
   <view class="bg-[#f5f7fa] flex flex-col h-screen overflow-hidden">
     <TopNavBar title="房间相册" backgroundColor="transparent" />
     <view class="p-[8px]">
-      <text class="ml-[4px] font-size-18 text-[#171717] font-500">全部({{ albumList.length }})</text>
+      <text class="ml-[4px] font-size-18 text-[#171717] font-[500]">全部({{ albumList.length }})</text>
     </view>
 
     <scroll-view scroll-y class="scroll-container overflow-auto">

src/pages/goods/index.vue

@@ -41,7 +41,7 @@
 
       <view class="btn rounded-[10px] flex flex-items-center ml-auto pl-[8px]" @click="navigateToPay(goodsData)">
         <image class="icon" src="https://oss.nianxx.cn/mp/static/version_101/common/btn.png" />
-        <text class="font-size-16 font-500 text-white">立即预定</text>
+        <text class="font-size-16 font-[500] text-white">立即预定</text>
       </view>
     </view>