feat(ui): heatmap view modes (all / jurist-reviewed / marked)

A segmented toggle over the heatmap: 'Alle' shows every evaluation,
'Geprüft (N)' filters to jurist-confirmed ones, 'Markiert' shows all
with a confirm-green check on the reviewed points. Jurists are
optional — the platform works without them and the default is 'Alle';
review only confirms a figure. Empty filtered view gets its own hint.

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

app/lib/pages/heatmap_page.dart

@@ -10,6 +10,19 @@ import '../widgets/reclaim_card.dart';
 import '../widgets/tier_badge.dart';
 import 'norm_detail_page.dart';
 
+/// Heatmap view modes. The platform works WITHOUT jurists — a jurist
+/// pass only *confirms* an evaluation — so the default shows all.
+enum _HeatmapView {
+  /// Every evaluation, jurist-reviewed or not.
+  all,
+
+  /// Only evaluations a jurist has confirmed.
+  reviewedOnly,
+
+  /// All evaluations, but reviewed ones carry a confirm marker.
+  marked,
+}
+
 class HeatmapPage extends StatefulWidget {
   const HeatmapPage({super.key, required this.repository});
 
@@ -21,6 +34,7 @@ class HeatmapPage extends StatefulWidget {
 
 class _HeatmapPageState extends State<HeatmapPage> {
   late Future<List<Evaluation>> _future;
+  _HeatmapView _view = _HeatmapView.all;
 
   @override
   void initState() {
@@ -45,6 +59,9 @@ class _HeatmapPageState extends State<HeatmapPage> {
                       child: CircularProgressIndicator());
                 }
                 final items = snap.data!;
+                final shown = _view == _HeatmapView.reviewedOnly
+                    ? items.where((e) => e.isReviewed).toList()
+                    : items;
                 return Column(
                   crossAxisAlignment: CrossAxisAlignment.start,
                   children: [
@@ -58,15 +75,29 @@ class _HeatmapPageState extends State<HeatmapPage> {
                         color: ReclaimColors.mute,
                       ),
                     ),
+                    if (items.isNotEmpty) ...[
+                      const SizedBox(height: ReclaimSpace.md),
+                      _ViewModeSelector(
+                        view: _view,
+                        reviewedCount:
+                            items.where((e) => e.isReviewed).length,
+                        total: items.length,
+                        onChanged: (v) => setState(() => _view = v),
+                      ),
+                    ],
                     const SizedBox(height: ReclaimSpace.lg),
                     Expanded(
                       child: items.isEmpty
                           ? _EmptyHubState(repository: widget.repository)
+                          : shown.isEmpty
+                              ? const _NoReviewedState()
                               : ReclaimCard(
                               accent: true,
                               expand: true,
                               child: HeatmapGrid(
-                                evaluations: items,
+                                evaluations: shown,
+                                markReviewed:
+                                    _view == _HeatmapView.marked,
                                 onTap: (e) {
                                   Navigator.of(context).push(
                                     MaterialPageRoute(
@@ -88,7 +119,7 @@ class _HeatmapPageState extends State<HeatmapPage> {
                       spacing: ReclaimSpace.md,
                       runSpacing: ReclaimSpace.sm,
                       children: [
-                        for (final e in items)
+                        for (final e in shown)
                           InkWell(
                             onTap: () {
                               Navigator.of(context).push(
@@ -375,6 +406,97 @@ class _EmptyHubState extends StatelessWidget {
   }
 }
 
+/// Heatmap view-mode toggle: all / jurist-reviewed only / marked.
+class _ViewModeSelector extends StatelessWidget {
+  const _ViewModeSelector({
+    required this.view,
+    required this.reviewedCount,
+    required this.total,
+    required this.onChanged,
+  });
+
+  final _HeatmapView view;
+  final int reviewedCount;
+  final int total;
+  final ValueChanged<_HeatmapView> onChanged;
+
+  @override
+  Widget build(BuildContext context) {
+    final t = Theme.of(context).textTheme;
+    return Row(
+      children: [
+        const Icon(Icons.visibility_outlined,
+            size: 16, color: ReclaimColors.mute),
+        const SizedBox(width: ReclaimSpace.sm),
+        Text('Ansicht',
+            style: t.labelLarge?.copyWith(color: ReclaimColors.mute)),
+        const SizedBox(width: ReclaimSpace.md),
+        SegmentedButton<_HeatmapView>(
+          showSelectedIcon: false,
+          style: const ButtonStyle(visualDensity: VisualDensity.compact),
+          segments: [
+            const ButtonSegment(
+              value: _HeatmapView.all,
+              label: Text('Alle'),
+              icon: Icon(Icons.scatter_plot_outlined, size: 15),
+            ),
+            ButtonSegment(
+              value: _HeatmapView.reviewedOnly,
+              label: Text('Geprüft ($reviewedCount)'),
+              icon: const Icon(Icons.verified_outlined, size: 15),
+            ),
+            const ButtonSegment(
+              value: _HeatmapView.marked,
+              label: Text('Markiert'),
+              icon: Icon(Icons.label_important_outline, size: 15),
+            ),
+          ],
+          selected: {view},
+          onSelectionChanged: (s) => onChanged(s.first),
+        ),
+      ],
+    );
+  }
+}
+
+/// Shown when the 'jurist-reviewed only' filter leaves nothing.
+class _NoReviewedState extends StatelessWidget {
+  const _NoReviewedState();
+
+  @override
+  Widget build(BuildContext context) {
+    final t = Theme.of(context).textTheme;
+    return ReclaimCard(
+      accent: true,
+      expand: true,
+      child: Center(
+        child: ConstrainedBox(
+          constraints: const BoxConstraints(maxWidth: 440),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              const Icon(Icons.verified_outlined,
+                  size: 40, color: ReclaimColors.mute),
+              const SizedBox(height: ReclaimSpace.md),
+              Text('Noch keine juristen-geprüften Auswertungen',
+                  style: t.headlineSmall),
+              const SizedBox(height: ReclaimSpace.sm),
+              Text(
+                'Die Plattform funktioniert auch ohne Juristen — wechsle '
+                'auf „Alle", um alle Auswertungen zu sehen. Ein '
+                'Juristen-Review bestätigt eine Auswertung zusätzlich.',
+                style: t.bodyLarge
+                    ?.copyWith(color: ReclaimColors.mute, height: 1.4),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+
 class _MiniLabel extends StatelessWidget {
   const _MiniLabel({required this.symbol, required this.text});
 

app/lib/widgets/heatmap_grid.dart

@@ -14,11 +14,16 @@ class HeatmapGrid extends StatefulWidget {
     super.key,
     required this.evaluations,
     this.onTap,
+    this.markReviewed = false,
   });
 
   final List<Evaluation> evaluations;
   final void Function(Evaluation)? onTap;
 
+  /// When true, points whose evaluation a jurist confirmed get a
+  /// confirm marker (used by the heatmap's "Markiert" view mode).
+  final bool markReviewed;
+
   @override
   State<HeatmapGrid> createState() => _HeatmapGridState();
 }
@@ -45,6 +50,7 @@ class _HeatmapGridState extends State<HeatmapGrid> {
               painter: _HeatmapPainter(
                 evaluations: widget.evaluations,
                 hoverIndex: _hoverIndex,
+                markReviewed: widget.markReviewed,
                 theme: Theme.of(context),
               ),
               size: size,
@@ -110,11 +116,13 @@ class _HeatmapPainter extends CustomPainter {
   _HeatmapPainter({
     required this.evaluations,
     required this.hoverIndex,
+    required this.markReviewed,
     required this.theme,
   });
 
   final List<Evaluation> evaluations;
   final int? hoverIndex;
+  final bool markReviewed;
   final ThemeData theme;
 
   @override
@@ -217,6 +225,33 @@ class _HeatmapPainter extends CustomPainter {
       canvas.drawCircle(c, r, body);
       canvas.drawCircle(c, r, ring);
 
+      // Jurist-confirmed marker (heatmap "Markiert" mode): a small
+      // confirm-green dot with a white check at the point's NE edge.
+      if (markReviewed && e.isReviewed) {
+        final m = Offset(c.dx + r * 0.72, c.dy - r * 0.72);
+        canvas.drawCircle(
+            m, 5.5, Paint()..color = ReclaimColors.reviewConfirmed);
+        canvas.drawCircle(
+            m,
+            5.5,
+            Paint()
+              ..color = theme.colorScheme.surface
+              ..style = PaintingStyle.stroke
+              ..strokeWidth = 1.5);
+        final check = Path()
+          ..moveTo(m.dx - 2.4, m.dy + 0.2)
+          ..lineTo(m.dx - 0.6, m.dy + 2.0)
+          ..lineTo(m.dx + 2.6, m.dy - 2.2);
+        canvas.drawPath(
+            check,
+            Paint()
+              ..color = theme.colorScheme.surface
+              ..style = PaintingStyle.stroke
+              ..strokeWidth = 1.4
+              ..strokeCap = StrokeCap.round
+              ..strokeJoin = StrokeJoin.round);
+      }
+
       _drawText(
         canvas,
         '${e.norm.jurabk} ${e.norm.paragraph}',
@@ -303,5 +338,6 @@ class _HeatmapPainter extends CustomPainter {
   @override
   bool shouldRepaint(covariant _HeatmapPainter old) =>
       old.hoverIndex != hoverIndex ||
+      old.markReviewed != markReviewed ||
       old.evaluations.length != evaluations.length;
 }