v1.0.7: updater, website button, timer sync indicator, server flow fix

- App: manual update checker (GitHub API, Play Store redirect)
- App: website button in sidebar
- App: timer_box shows Connecting/Syncing spinner during handshake
- App: synced app_config.example.dart with app_config.dart
- Sidebar: 6 rows (added Website, Check for updates)
- Server: add_vless_client now includes flow xtls-rprx-vision
- Deps: added package_info_plus
- Version bump: 1.0.6+10 → 1.0.7+11
- CHANGELOG.md created

lib/components/sidebar_contents/website_button.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+import 'package:url_launcher/url_launcher.dart';
+import 'package:revoltvpn/logic/app_colors.dart';
+
+class WebsiteButton extends StatelessWidget {
+  const WebsiteButton({super.key});
+
+  static Future<void> launchWebsite() async {
+    final Uri url = Uri.parse('https://getrevolt.app');
+    if (!await launchUrl(url, mode: LaunchMode.externalApplication)) {
+      debugPrint('Could not launch $url');
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return IconButton(
+      icon: const Icon(Icons.language, color: AppColors.textWhite, size: 28),
+      onPressed: launchWebsite,
+      tooltip: 'Website',
+      splashRadius: 24,
+    );
+  }
+}