fix(profiles): remount profile session

close #1371

lib/navigation/profile_navigation_scope.dart

@@ -0,0 +1,77 @@
+import 'package:flutter/material.dart';
+
+/// Tracks the currently mounted profile-scoped navigator and main
+/// ScaffoldMessenger without making their GlobalKeys app-lifetime widgets.
+///
+/// The keys are created inside the profile session and registered here only so
+/// app-global helpers (mouse back, background snackbars) can reach the active
+/// profile surface. A profile switch unregisters the old keys before the new
+/// session registers fresh ones.
+class ProfileNavigationRegistry {
+  GlobalKey<NavigatorState>? _navigatorKey;
+  GlobalKey<ScaffoldMessengerState>? _mainScaffoldMessengerKey;
+
+  NavigatorState? get navigator => _navigatorKey?.currentState;
+  ScaffoldMessengerState? get mainScaffoldMessenger => _mainScaffoldMessengerKey?.currentState;
+
+  void attachNavigator(GlobalKey<NavigatorState> key) {
+    _navigatorKey = key;
+  }
+
+  void detachNavigator(GlobalKey<NavigatorState> key) {
+    if (identical(_navigatorKey, key)) {
+      _navigatorKey = null;
+    }
+  }
+
+  void attachMainScaffoldMessenger(GlobalKey<ScaffoldMessengerState> key) {
+    _mainScaffoldMessengerKey = key;
+  }
+
+  void detachMainScaffoldMessenger(GlobalKey<ScaffoldMessengerState> key) {
+    if (identical(_mainScaffoldMessengerKey, key)) {
+      _mainScaffoldMessengerKey = null;
+    }
+  }
+
+  Future<bool> maybePopProfileRoute() async {
+    final state = navigator;
+    if (state == null) return false;
+    return state.maybePop();
+  }
+}
+
+final profileNavigationRegistry = ProfileNavigationRegistry();
+
+class ProfileNavigationScope extends InheritedWidget {
+  const ProfileNavigationScope({
+    super.key,
+    required this.navigatorKey,
+    required this.routeObserver,
+    required this.mainScaffoldMessengerKey,
+    required super.child,
+  });
+
+  final GlobalKey<NavigatorState> navigatorKey;
+  final RouteObserver<PageRoute<dynamic>> routeObserver;
+  final GlobalKey<ScaffoldMessengerState> mainScaffoldMessengerKey;
+
+  static ProfileNavigationScope of(BuildContext context) {
+    final scope = context.dependOnInheritedWidgetOfExactType<ProfileNavigationScope>();
+    if (scope == null) {
+      throw StateError('ProfileNavigationScope is required for profile routes.');
+    }
+    return scope;
+  }
+
+  static ProfileNavigationScope? maybeOf(BuildContext context) {
+    return context.dependOnInheritedWidgetOfExactType<ProfileNavigationScope>();
+  }
+
+  @override
+  bool updateShouldNotify(ProfileNavigationScope oldWidget) {
+    return navigatorKey != oldWidget.navigatorKey ||
+        routeObserver != oldWidget.routeObserver ||
+        mainScaffoldMessengerKey != oldWidget.mainScaffoldMessengerKey;
+  }
+}