feat(hub): list installed capabilities from the connected hub

HubCapabilitiesCard wires HubClient.listCapabilities() into the
hub-status page below the connection form: once the app starts
in hub mode and the connection is healthy, the card shows
capability@version, the providing module, and its kind for
every entry the hub reports.

In mock mode the card prints an explanatory hint instead of
loading, so no confusing empty-state appears when the user is
just browsing the demo data.

A small refresh-icon next to the heading lets the user re-poll
without a full page reload — useful right after a chain install
in another terminal.

Signed-off-by: flemming-it <sf@flemming.it>

app/lib/pages/hub_status_page.dart

@@ -4,6 +4,7 @@ import '../data/hub_endpoint.dart';
 import '../data/hub_repository.dart';
 import '../data/repository.dart';
 import '../theme/lawheatmap_tokens.dart';
+import '../widgets/hub_capabilities_card.dart';
 import '../widgets/lawheatmap_card.dart';
 
 /// Hub connection + settings. Read-only summary at the top, then
@@ -238,6 +239,8 @@ class _HubStatusPageState extends State<HubStatusPage> {
             ),
           ),
           const SizedBox(height: LawHeatmapSpace.lg),
+          HubCapabilitiesCard(repository: repo),
+          const SizedBox(height: LawHeatmapSpace.lg),
           LawHeatmapCard(
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,

app/lib/widgets/hub_capabilities_card.dart

@@ -0,0 +1,128 @@
+import 'package:chain_client_sdk/chain_client_sdk.dart' as chain;
+import 'package:flutter/material.dart';
+
+import '../data/hub_repository.dart';
+import '../data/repository.dart';
+import '../theme/lawheatmap_tokens.dart';
+import 'lawheatmap_card.dart';
+
+/// Lists the capabilities the connected hub has installed.
+/// Empty / explanatory state when the active repository is not
+/// a live [HubRepository]. Real wire to HubClient.listCapabilities().
+class HubCapabilitiesCard extends StatefulWidget {
+  const HubCapabilitiesCard({super.key, required this.repository});
+
+  final EvaluationRepository repository;
+
+  @override
+  State<HubCapabilitiesCard> createState() => _HubCapabilitiesCardState();
+}
+
+class _HubCapabilitiesCardState extends State<HubCapabilitiesCard> {
+  late Future<List<chain.CapabilityEntry>> _future;
+
+  @override
+  void initState() {
+    super.initState();
+    _future = _load();
+  }
+
+  Future<List<chain.CapabilityEntry>> _load() async {
+    final repo = widget.repository;
+    if (repo is! HubRepository || !repo.isHealthy) return const [];
+    return repo.client.listCapabilities();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final t = Theme.of(context).textTheme;
+    final repo = widget.repository;
+    final liveHub = repo is HubRepository && repo.isHealthy;
+
+    return LawHeatmapCard(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(children: [
+            Text('Installierte Capabilities', style: t.headlineSmall),
+            const Spacer(),
+            if (liveHub)
+              IconButton(
+                tooltip: 'Neu laden',
+                onPressed: () => setState(() => _future = _load()),
+                icon: const Icon(Icons.refresh),
+              ),
+          ]),
+          const SizedBox(height: LawHeatmapSpace.sm),
+          if (!liveHub)
+            Text(
+              'Sichtbar sobald die App im Hub-Modus startet und '
+              'der Hub erreichbar ist (siehe Verbindung oben).',
+              style: t.labelSmall?.copyWith(
+                color: LawHeatmapColors.mute,
+              ),
+            )
+          else
+            FutureBuilder<List<chain.CapabilityEntry>>(
+              future: _future,
+              builder: (context, snap) {
+                if (snap.connectionState == ConnectionState.waiting) {
+                  return const Padding(
+                    padding: EdgeInsets.all(LawHeatmapSpace.md),
+                    child: CircularProgressIndicator(),
+                  );
+                }
+                if (snap.hasError) {
+                  return Text('Fehler: ${snap.error}',
+                      style: t.labelLarge
+                          ?.copyWith(color: LawHeatmapColors.harmWarm));
+                }
+                final items = snap.data ?? const [];
+                if (items.isEmpty) {
+                  return Text(
+                    'Hub hat noch keine Capabilities installiert. '
+                    'Mit `chain install <name>` hinzufügen.',
+                    style: t.bodyLarge?.copyWith(
+                      color: LawHeatmapColors.mute,
+                    ),
+                  );
+                }
+                return Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    for (final c in items)
+                      Padding(
+                        padding: const EdgeInsets.symmetric(vertical: 4),
+                        child: Row(
+                          crossAxisAlignment: CrossAxisAlignment.start,
+                          children: [
+                            SizedBox(
+                              width: 280,
+                              child: Text(
+                                '${c.capability}@${c.version}',
+                                style: t.bodyLarge?.copyWith(
+                                  fontFamily: LawHeatmapTypography.mono,
+                                ),
+                              ),
+                            ),
+                            Expanded(
+                              child: Text(
+                                '${c.moduleName} ${c.moduleVersion}'
+                                '${c.kind.isEmpty ? "" : "  ·  ${c.kind}"}',
+                                style: t.labelSmall?.copyWith(
+                                  color: LawHeatmapColors.mute,
+                                ),
+                              ),
+                            ),
+                          ],
+                        ),
+                      ),
+                  ],
+                );
+              },
+            ),
+        ],
+      ),
+    );
+  }
+}