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/widgets/freshness_badge.dart

@@ -0,0 +1,74 @@
+import 'package:flutter/material.dart';
+
+import '../data/models.dart';
+import '../theme/reclaim_tokens.dart';
+
+/// Freshness badge — flags when a norm version is stale relative to
+/// the published source (amended upstream) or hasn't been reconciled.
+/// By design it renders NOTHING for [Freshness.current] (the common
+/// case shouldn't add noise) unless [alwaysShow] is set. Same chip
+/// shape as the scope/tier badges.
+class FreshnessBadge extends StatelessWidget {
+  const FreshnessBadge({
+    super.key,
+    required this.freshness,
+    this.note,
+    this.compact = false,
+    this.alwaysShow = false,
+  });
+
+  final Freshness freshness;
+
+  /// Optional plain-text hint of what changed (from Norm.supersededNote).
+  final String? note;
+  final bool compact;
+  final bool alwaysShow;
+
+  @override
+  Widget build(BuildContext context) {
+    if (!freshness.needsBadge && !alwaysShow) {
+      return const SizedBox.shrink();
+    }
+    final t = Theme.of(context).textTheme;
+    final color = switch (freshness) {
+      Freshness.current => ReclaimColors.signal,
+      Freshness.superseded => ReclaimColors.freshSuperseded,
+      Freshness.unknown => ReclaimColors.freshUnknown,
+    };
+    final icon = switch (freshness) {
+      Freshness.current => Icons.check_circle_outline,
+      Freshness.superseded => Icons.history_toggle_off,
+      Freshness.unknown => Icons.help_outline,
+    };
+    final label = compact ? freshness.label : 'Stand: ${freshness.label}';
+    return Tooltip(
+      message: '${freshness.description}'
+          '${note != null && note!.isNotEmpty ? '\n$note' : ''}',
+      child: Container(
+        padding: EdgeInsets.symmetric(
+          horizontal: compact ? 6 : ReclaimSpace.sm,
+          vertical: compact ? 2 : 4,
+        ),
+        decoration: BoxDecoration(
+          color: color.withValues(alpha: 0.18),
+          border: Border.all(color: color.withValues(alpha: 0.55)),
+          borderRadius: const BorderRadius.all(ReclaimRadius.sm),
+        ),
+        child: Row(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Icon(icon, size: compact ? 12 : 14, color: color),
+            const SizedBox(width: 6),
+            Text(
+              label,
+              style: (compact ? t.labelSmall : t.labelLarge)?.copyWith(
+                color: color,
+                fontWeight: FontWeight.w600,
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}