fix: 静默登录失败时不跳回登录页

public/app.js

@@ -256,8 +256,10 @@ async function loginWithKey(key, surfaceError = true) {
     localStorage.removeItem(MODEL_STORAGE);
     localStorage.removeItem(ACCESS_KEY_STORAGE);
     renderModelDropdown();
-    if (surfaceError) setLoginError(error.message || '登录失败');
+    if (surfaceError) {
+      setLoginError(error.message || '登录失败');
       showLogin();
+    }
     return false;
   }
 }

public/styles.css

@@ -587,7 +587,8 @@ body.theme-light .md-pre { background: #f3f4f6; border-color: rgba(15,23,42,.08)
     height: 100dvh;
     min-height: 0;
     overflow: hidden;
-    grid-template-rows: auto minmax(0, 1fr) auto;
+    display: flex;
+    flex-direction: column;
   }
   .topbar {
     gap: 8px;
@@ -623,6 +624,8 @@ body.theme-light .md-pre { background: #f3f4f6; border-color: rgba(15,23,42,.08)
 
   .messages {
     height: 100%;
+    flex: 1 1 0;
+    min-height: 0;
     -webkit-overflow-scrolling: touch;
   }
   .empty-state,