fix: update login page logo to use project logo.png

frontend/src/views/auth/Login.vue

@@ -2,11 +2,7 @@
   <div class="auth-page">
     <div class="auth-card">
       <div class="auth-logo">
-        <div class="logo-icon">
-          <svg viewBox="0 0 24 24" fill="currentColor" width="24" height="24">
-            <path d="M12 2L2 7l10 5 10-5-10-5zM2 17l10 5 10-5M2 12l10 5 10-5"/>
-          </svg>
-        </div>
+        <img :src="logoImg" alt="Logo" class="logo-icon" />
         <h2>{{ $t('common.login') }}</h2>
       </div>
       <el-form :model="form" :rules="rules" ref="formRef" @submit.prevent="handleLogin">
@@ -36,6 +32,7 @@ import { useRouter } from 'vue-router'
 import { ElMessage } from 'element-plus'
 import { useI18n } from 'vue-i18n'
 import { useUserStore } from '../../store/user'
+import logoImg from '../../assets/logo.png'
 
 const router = useRouter()
 const { t } = useI18n()
@@ -104,12 +101,8 @@ async function handleLogin() {
   width: 48px;
   height: 48px;
   border-radius: 12px;
-  background: linear-gradient(135deg, #4e6ef2, #7c5cfc);
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  color: #fff;
   margin-bottom: 16px;
+  object-fit: contain;
 }
 
 .auth-logo h2 {