feat(ui): scope, freshness and jurist-review badges + live empty-state

Adds three dark-first chip badges in the TierBadge pattern:
- Jurisdiction (Berlin/DE/EU/International) — derived from the ELI,
  surfaced on the norms list, detail header and heatmap chips/hover.
- Freshness (aktuell/geaendert/ungeprueft) — flags norms amended
  upstream (standDate + sourceSha256); renders only when stale.
- Jurist review — marks evaluations a trusted jurist has confirmed
  (optional; the figure stands on its own).
Models gain Jurisdiction/Freshness enums, Norm.freshness/supersededNote
and Evaluation.reviewedBy/reviewedAt; HubRepository parses them from
the flow bag (ELI fallback). HeatmapPage shows a real empty-state
(hub-down vs no-evaluations) instead of a blank plot, and connect()
no longer throws on a failed probe.

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

app/lib/data/hub_repository.dart

@@ -36,10 +36,21 @@ class HubRepository implements EvaluationRepository {
       endpoint: endpoint,
       authToken: settings.authToken,
     );
-    final ok = await client.healthy().timeout(
-          const Duration(seconds: 4),
-          onTimeout: () => false,
-        );
+    // The probe must NEVER throw out of connect(): main() awaits
+    // this before runApp(), so any uncaught error here leaves the
+    // app on a blank page. A timeout maps to false; so does any
+    // transport error (e.g. a gRPC-web call against a plain-gRPC
+    // hub, or a refused connection) — the app then comes up in
+    // 'hub-down' state and shows the empty-state hint.
+    bool ok;
+    try {
+      ok = await client.healthy().timeout(
+            const Duration(seconds: 4),
+            onTimeout: () => false,
+          );
+    } catch (_) {
+      ok = false;
+    }
     return HubRepository._(client, settings, ok);
   }
 
@@ -97,14 +108,21 @@ class HubRepository implements EvaluationRepository {
     if (normJson == null) return null;
     final skmJson = _asMap(bag['skm']);
 
+    final eli = (normJson['eli'] as String?) ?? 'eli/unknown';
     final norm = Norm(
-      eli: (normJson['eli'] as String?) ?? 'eli/unknown',
+      eli: eli,
       title: (normJson['title'] as String?) ?? '(ohne Titel)',
       jurabk: (normJson['jurabk'] as String?) ?? '',
       paragraph: (normJson['paragraph'] as String?) ?? '',
+      jurisdiction: JurisdictionLabel.parse(
+        normJson['scope'] as String?,
+        eli: eli,
+      ),
       standDate: _parseTimestamp(event.timestamp),
       sourceUrl: (normJson['source_url'] as String?) ?? '',
       sourceSha256: (normJson['source_sha256'] as String?) ?? '',
+      freshness: _parseFreshness(normJson['freshness']),
+      supersededNote: normJson['superseded_note'] as String?,
       paragraphs: _parseParagraphs(normJson['paragraphs']),
     );
 
@@ -138,9 +156,26 @@ class HubRepository implements EvaluationRepository {
       auditEventId: event.eventId,
       notes: 'Live aus Hub-Flow ${event.flowName} '
           '(execution ${event.flowExecution.substring(0, 8.clamp(0, event.flowExecution.length))}).',
+      // Jurist sign-off is recorded by the approval, not the flow
+      // bag. Until the review-rewrite wires approvals in, these stay
+      // null (= unreviewed) unless the bag carries them explicitly.
+      reviewedBy: bag['reviewed_by'] as String?,
+      reviewedAt: DateTime.tryParse(
+          (bag['reviewed_at'] as String?) ?? ''),
     );
   }
 
+  static Freshness _parseFreshness(dynamic v) {
+    switch ((v as String?)?.trim().toLowerCase()) {
+      case 'superseded' || 'amended' || 'geändert' || 'stale':
+        return Freshness.superseded;
+      case 'unknown' || 'ungeprüft':
+        return Freshness.unknown;
+      default:
+        return Freshness.current;
+    }
+  }
+
   static Map<String, dynamic>? _asMap(dynamic v) =>
       v is Map<String, dynamic> ? v : null;