feat: federation panel + Dart SDK federation methods (0.70.0)

A new 'Föderation' destination (primary side) lists connected
satellites — name, region, version, wire version, advertised
capabilities — and adds them in one step: 'Add satellite' issues a
single-use bootstrap token bundled with the primary CA as a
ready-to-paste satellite config (the bundled CA makes the first
connect tamper-proof). Localized EN + DE, in-app help doc. Uses the
new HubService.listSatellites / issueSatelliteToken wrapping the
SDK's federation methods.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/main.dart

@@ -16,6 +16,7 @@ import 'l10n/app_localizations.dart';
 import 'pages/approvals.dart';
 import 'pages/audit.dart';
 import 'pages/doctor.dart';
+import 'pages/federation.dart';
 import 'pages/flows.dart';
 import 'pages/store.dart';
 import 'pages/welcome.dart';
@@ -27,7 +28,7 @@ import 'widgets/widgets.dart';
 /// Studio's own build version. Bump on every UI commit so the
 /// running app self-identifies — visible in the sidebar header
 /// and quick-glance proof that you're seeing the current build.
-const String kStudioVersion = '0.69.0';
+const String kStudioVersion = '0.70.0';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -348,6 +349,12 @@ class StudioShellState extends State<StudioShell> {
       selectedIcon: Icons.inbox,
       page: ApprovalsPage(),
     ),
+    _NavPage(
+      id: 'federation',
+      icon: Icons.hub_outlined,
+      selectedIcon: Icons.hub,
+      page: FederationPage(),
+    ),
   ];
 
   /// Pending-approval count surfaced as a sidebar badge so the
@@ -1397,6 +1404,8 @@ class _NavPage {
         return l.navAudit;
       case 'approvals':
         return l.navApprovals;
+      case 'federation':
+        return l.navFederation;
       default:
         return id;
     }