style: replace legacy padding classes with inline pixel values

Remove the unused padding.scss stylesheet and its import from the main SCSS entrypoint. Update all legacy padding utility class names across every Vue component to use inline pixel-based utility classes (such as replacing `pl-12` with `pl-[12px]`). Also clean up extraneous whitespace and line breaks in component templates for improved readability.

src/pages/ChatMain/ChatMainList/index.vue

@@ -22,8 +22,8 @@
 
     <view v-show="tabIndex === 0" class="discovery-shell flex-full" @touchstart.capture="handleDiscoveryPanelTouchStart"
       @touchstart="handleDiscoveryPanelTouchStart" @touchmove.capture="handleDiscoveryPanelTouchMove"
-      @touchmove="handleDiscoveryPanelTouchMove"
-      @touchend="handleDiscoveryPanelTouchEnd" @touchcancel="handleDiscoveryPanelTouchEnd">
+      @touchmove="handleDiscoveryPanelTouchMove" @touchend="handleDiscoveryPanelTouchEnd"
+      @touchcancel="handleDiscoveryPanelTouchEnd">
       <view class="home-welcome-panel">
         <HomeWelcome class="flex-shrink-0" :mainPageDataModel="mainPageDataModel" />
       </view>
@@ -138,7 +138,7 @@
     </scroll-view>
 
     <!-- 输入框区域 -->
-    <view class="pb-safe-area">
+    <view class="pb-[20px]">
       <ChatQuickAccess />
       <ChatInputArea ref="inputAreaRef" v-model="inputMessage" :holdKeyboard="holdKeyboard"
         :is-session-active="isSessionActive" :stop-request="stopRequest" @send="sendMessageAction"