feat: 优化 URL 生成逻辑并添加同步品牌信息功能

lib/main.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -124,7 +125,6 @@ class _H5ShellPageState extends State<H5ShellPage> with WidgetsBindingObserver {
     WidgetsBinding.instance.addObserver(this);
     _homeUrl = AppConfig.homeUrl(
       appName: widget.shellBranding.appName,
-      appLogo: widget.shellBranding.appLogo,
     );
     _controller = _buildController()..loadRequest(Uri.parse(_homeUrl));
   }
@@ -187,6 +187,7 @@ class _H5ShellPageState extends State<H5ShellPage> with WidgetsBindingObserver {
             }
           },
           onPageFinished: (_) {
+            unawaited(_syncShellBranding());
             if (mounted) {
               setState(() {
                 _progress = 100;
@@ -253,6 +254,23 @@ class _H5ShellPageState extends State<H5ShellPage> with WidgetsBindingObserver {
     }
   }
 
+  Future<void> _syncShellBranding() {
+    final payload = jsonEncode({
+      'name': widget.shellBranding.appName,
+      'logo': widget.shellBranding.appLogo,
+    });
+    final script = '''
+(() => {
+  try {
+    const brand = $payload;
+    window.sessionStorage.setItem('OPENIM_FLUTTER_SHELL_BRAND', JSON.stringify(brand));
+    window.dispatchEvent(new CustomEvent('openim-shell-branding-updated', { detail: brand }));
+  } catch (_) {}
+})();
+''';
+    return _runJavaScriptSafely(script);
+  }
+
   Future<void> _stopWebMedia() {
     return _runJavaScriptSafely(_stopWebMediaScript);
   }