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/l10n/app_localizations_en.dart

@@ -2635,4 +2635,67 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get hubUnreachableOpenSettings => 'Open Settings';
+
+  @override
+  String get navFederation => 'Federation';
+
+  @override
+  String get federationTitle => 'Federation';
+
+  @override
+  String get federationReloadTooltip => 'Reload satellites';
+
+  @override
+  String get federationAddSatellite => 'Add satellite';
+
+  @override
+  String get federationEmptyTitle => 'No satellites connected';
+
+  @override
+  String get federationEmptyHint =>
+      'Connect another hub as a satellite to run capabilities on it. Issue an enrollment token to get started.';
+
+  @override
+  String get federationPillConnected => 'connected';
+
+  @override
+  String get federationRegionNone => 'no region';
+
+  @override
+  String federationCapabilities(int count) {
+    return '$count advertised capabilities';
+  }
+
+  @override
+  String get federationAddDialogTitle => 'Issue an enrollment token';
+
+  @override
+  String get federationNameLabel => 'Satellite name';
+
+  @override
+  String get federationIssueButton => 'Issue';
+
+  @override
+  String federationIssueFailed(String error) {
+    return 'Could not issue token: $error';
+  }
+
+  @override
+  String federationEnrollmentTitle(String name) {
+    return 'Enroll $name';
+  }
+
+  @override
+  String get federationTokenLabel => 'Bootstrap token (single use)';
+
+  @override
+  String get federationConfigLabel =>
+      'Satellite config (paste into the satellite)';
+
+  @override
+  String get federationCopied => 'Copied to clipboard';
+
+  @override
+  String get federationEnrollmentHint =>
+      'Hand the token to the satellite operator over a secure channel. The bundled CA makes the satellite\'s first connect tamper-proof.';
 }