fix: переход по ссылкам и диплинки с миниапов

lib/core/utils/link_opener.dart

@@ -6,6 +6,21 @@ import 'package:url_launcher/url_launcher.dart';
 import '../../frontend/widgets/custom_notification.dart';
 import '../../frontend/widgets/max_link_handler.dart';
 
+const Set<String> _webViewSchemes = {
+  'http',
+  'https',
+  'about',
+  'data',
+  'blob',
+  'javascript',
+  'file',
+};
+
+bool leavesWebView(String? scheme) {
+  if (scheme == null || scheme.isEmpty) return false;
+  return !_webViewSchemes.contains(scheme.toLowerCase());
+}
+
 Future<void> openExternalUrl(BuildContext context, String url) async {
   if (await tryHandleMaxLink(context, url)) return;
   if (!context.mounted) return;

lib/frontend/screens/webapp/web_app_screen.dart

@@ -182,8 +182,13 @@ class _WebAppScreenState extends State<WebAppScreen> {
       return NavigationActionPolicy.CANCEL;
     }
     final handler = widget.shouldOverrideUrlLoading;
-    if (handler == null) return NavigationActionPolicy.ALLOW;
+    if (handler != null) return handler(controller, action, _launch?.url);
-    return handler(controller, action, _launch?.url);
+
+    if (uri != null && leavesWebView(uri.scheme)) {
+      if (mounted) await openExternalUrl(context, uri.toString());
+      return NavigationActionPolicy.CANCEL;
+    }
+    return NavigationActionPolicy.ALLOW;
   }
 
   @override

test/webview_scheme_test.dart

@@ -0,0 +1,36 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:komet/core/links/max_link.dart';
+import 'package:komet/core/utils/link_opener.dart';
+
+void main() {
+  group('leavesWebView', () {
+    test('keeps page navigation inside the web view', () {
+      for (final scheme in [
+        'http',
+        'https',
+        'HTTPS',
+        'about',
+        'data',
+        'blob',
+      ]) {
+        expect(leavesWebView(scheme), isFalse, reason: scheme);
+      }
+    });
+
+    test('hands app schemes over to the app', () {
+      for (final scheme in ['max', 'MAX', 'komet', 'tel', 'mailto', 'intent']) {
+        expect(leavesWebView(scheme), isTrue, reason: scheme);
+      }
+    });
+
+    test('treats a missing scheme as in-page', () {
+      expect(leavesWebView(null), isFalse);
+      expect(leavesWebView(''), isFalse);
+    });
+  });
+
+  test('a max deep link from a web view resolves to in-app content', () {
+    expect(MaxLink.parse('max://max.ru/somechannel'), isA<MaxContentLink>());
+    expect(MaxLink.isMaxLink('max://max.ru/?cid=424242'), isTrue);
+  });
+}