fix: login

ui/src/views/Login.vue

@@ -2,7 +2,7 @@
     <div class="login-page">
         <div class="login-card">
             <div class="login-brand">
-                <div class="brand-ornament">◆</div>
+                <img src="/favicon.svg" class="brand-ornament" alt="" />
                 <h1>Mercury</h1>
                 <p class="brand-sub">Administration Console</p>
                 <div class="brand-rule"></div>
@@ -103,6 +103,7 @@ async function handleLogin() {
     opacity: 0.7;
     letter-spacing: 0.3em;
     margin-bottom: 0.4rem;
+    max-width: 100px;
 }
 
 .login-brand h1 {