refactor: remove margin utils, use inline pixel spacing

Delete the src/static/scss/margin.scss utility file, update all component templates to replace pre-defined margin classes with inline arbitrary pixel values (e.g. mb-[4px] instead of mb-4), and clean up long template lines for better readability.

src/pages/ChatModule/ZModuleBase/index.vue

@@ -2,7 +2,7 @@
   <view class="container w-full border-ff overflow-hidden rounded-[24px] flex flex-col">
     <!-- 占位撑开 -->
     <view class="w-vw"></view>
-    <view class="flex flex-col m-4 rounded-[24px]">
+    <view class="flex flex-col m-[4px] rounded-[24px]">
       <slot name="content"></slot>
     </view>
   </view>