[FEAT] 完善個人檔案功能：新增頭像即時上傳、麵包屑導覽、版面寬度優化與日期格式統一

resources/views/admin/placeholder.blade.php

@@ -1,7 +1,7 @@
 @extends('layouts.admin')
 
 @section('content')
-<div class="max-w-7xl mx-auto">
+<div>
     <div class="bg-white dark:bg-gray-800 rounded-lg shadow-lg p-8 text-center border border-gray-200 dark:border-gray-700">
         <div class="mb-6">
             <svg class="mx-auto h-24 w-24 text-gray-400 dark:text-gray-500" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke="currentColor">