feat: 更新 homeUrl 方法以支持传递应用 logo，增强 URL 生成逻辑

test/widget_test.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:im_webview_app/config/app_config.dart';
 import 'package:im_webview_app/main.dart';
 
 void main() {
@@ -9,4 +10,18 @@ void main() {
       isA<Widget>(),
     );
   });
+
+  test('passes shell branding name and logo to the H5 URL', () {
+    const logo = 'data:image/png;base64,abc+/=';
+
+    final uri = Uri.parse(
+      AppConfig.homeUrl(appName: 'Shell Test', appLogo: logo),
+    );
+
+    expect(uri.queryParameters['flutter_shell'], '1');
+    expect(uri.queryParameters['shell_app_name'], 'Shell Test');
+    expect(uri.queryParameters.containsKey('shell_app_logo'), isFalse);
+    expect(uri.toString(), isNot(contains('%25')));
+    expect(Uri.splitQueryString(uri.fragment)['shell_app_logo'], logo);
+  });
 }