style(assets): 更新项目logo和头像图片

- 将登录页面的logo从ckp.png替换为xj.png
- 将导航栏用户头像从xujie.png替换为xj.png
- 将模态框标题中的图片从xujie.png替换为xj.png

src/views/common/login.vue

@@ -8,7 +8,7 @@
       <div style="width: 35%; display: flex; justify-content: center; align-items: center;">
         <div style="max-width: 400px; width: 100%; padding: 40px 30px; background: #ffffff; border-radius: 12px; box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);">
           <div style="text-align: center;">
-            <img width="60%" height="72" style="object-fit: contain" src="~@/assets/img/ckp.png">
+            <img width="60%" height="72" style="object-fit: contain" src="~@/assets/img/xj.png">
           </div>
           <h3 class="login-title">用户登录</h3>
           <el-form :model="dataForm" :rules="dataRule" ref="dataForm" @keyup.enter.native="dataFormSubmit()" status-icon>

src/views/main-navbar.vue

@@ -52,7 +52,7 @@
         <el-menu-item class="site-navbar__avatar" index="4">
           <el-dropdown :show-timeout="0" placement="bottom">
                       <span class="el-dropdown-link custom-avatar">
-                        <img src="~@/assets/img/xujie.png" :alt="userName">{{ userName }}
+                        <img src="~@/assets/img/xj.png" :alt="userName">{{ userName }}
                         <!--                        <img src="~@/assets/img/avatar.png" :alt="userName">{{ userName }}-->
                       </span>
             <el-dropdown-menu slot="dropdown">
@@ -71,7 +71,7 @@
 
     <el-dialog append-to-body top="26vh" :show-close="false" :close-on-click-modal="true" v-drag :visible.sync="revisionModalFlag" width="335px">
       <div slot="title" style="text-align: center">
-        <img src="~@/assets/img/xujie.png" style="width: 115px;height: 45px;vertical-align: middle;object-fit: contain;">
+        <img src="~@/assets/img/xj.png" style="width: 115px;height: 45px;vertical-align: middle;object-fit: contain;">
         <!--        <img src="~@/assets/img/avatar.png" style="width: 115px;height: 45px;vertical-align: middle;object-fit: contain;">-->
       </div>
       <div style="display: flex;justify-content: space-between;">