feat: 对齐常驻商城与七鱼客服交互

- 同步商城 H5 登录态与原生 token
- 完善商城/原生 tab 切换、动画及返回交互
- 修复七鱼客服键盘避让和状态栏恢复
- 调整开屏跳过按钮与登录入口交互

lib/common/util/app_link_util.dart

@@ -0,0 +1,60 @@
+import 'dart:io' show Platform;
+
+import 'package:android_intent_plus/android_intent.dart';
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:url_launcher/url_launcher.dart';
+
+typedef AndroidIntentLauncher = Future<void> Function(AndroidIntent intent);
+
+abstract final class AppLinkUtil {
+  static final _androidPackageNamePattern = RegExp(
+    r'^[A-Za-z][A-Za-z0-9_]*(?:\.[A-Za-z][A-Za-z0-9_]*)+$',
+  );
+
+  static String targetAppFromUrl(String urlString) {
+    final value = Uri.tryParse(urlString)?.queryParameters['targetApp']?.trim();
+    if (value == null || !_androidPackageNamePattern.hasMatch(value)) return '';
+    return value;
+  }
+
+  static Future<bool> openExternal(Uri uri, {String packageName = ''}) =>
+      AppLinkLauncher(
+        isAndroid: () => !kIsWeb && Platform.isAndroid,
+        launchAndroidIntent: (intent) => intent.launch(),
+      ).openExternal(uri, packageName: packageName);
+}
+
+class AppLinkLauncher {
+  const AppLinkLauncher({
+    required this.isAndroid,
+    required this.launchAndroidIntent,
+    this.launchExternal,
+  });
+
+  final bool Function() isAndroid;
+  final AndroidIntentLauncher launchAndroidIntent;
+  final Future<bool> Function(Uri uri)? launchExternal;
+
+  Future<bool> openExternal(Uri uri, {String packageName = ''}) async {
+    if (uri.host.isEmpty ||
+        (uri.scheme.toLowerCase() != 'http' &&
+            uri.scheme.toLowerCase() != 'https')) {
+      return false;
+    }
+    if (isAndroid() && packageName.trim().isNotEmpty) {
+      try {
+        await launchAndroidIntent(
+          AndroidIntent(
+            action: 'action_view',
+            data: uri.toString(),
+            package: packageName.trim(),
+          ),
+        );
+        return true;
+      } catch (_) {}
+    }
+    final launcher = launchExternal;
+    if (launcher != null) return launcher(uri);
+    return launchUrl(uri, mode: LaunchMode.externalApplication);
+  }
+}