feat(insights): first isights impemetation

lib/features/insights/presentation/charts/bmi_chart.dart

@@ -0,0 +1,84 @@
+import 'package:eatvio_app/features/insights/models/insights_payload_model.dart';
+import 'package:eatvio_app/features/insights/presentation/charts/insights_chart_common.dart';
+import 'package:eatvio_app/features/insights/presentation/widgets/insights_colors.dart';
+import 'package:eatvio_app/generated/l10n.dart';
+import 'package:flutter/material.dart';
+import 'package:syncfusion_flutter_charts/charts.dart';
+
+/// График ИМТ с цветными зонами: норма 18.5–25, избыточная масса 25–30, ожирение 30–40.
+class BmiChart extends StatelessWidget {
+  const BmiChart({super.key, required this.model});
+
+  final BmiChartModel model;
+
+  @override
+  Widget build(BuildContext context) {
+    final points = buildPoints(model.labels, model.values);
+    if (points.isEmpty) {
+      return InsightsChartPlaceholder(text: model.deltaText);
+    }
+    final s = S.of(context);
+    final range = paddedRange(points.map((e) => e.value), minPadding: 2);
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        SizedBox(
+          height: insightsChartHeight,
+          child: SfCartesianChart(
+            key: const Key('insights_bmi_chart'),
+            margin: EdgeInsets.zero,
+            plotAreaBorderWidth: 0,
+            primaryXAxis: buildInsightsCategoryAxis(),
+            primaryYAxis: buildInsightsValueAxis(
+              unit: s.insights_unit_bmi,
+              min: range.min,
+              max: range.max,
+              plotBands: const [
+                PlotBand(
+                  start: 18.5,
+                  end: 25,
+                  color: InsightsColors.bmiNormalZone,
+                ),
+                PlotBand(
+                  start: 25,
+                  end: 30,
+                  color: InsightsColors.bmiOverweightZone,
+                ),
+                PlotBand(
+                  start: 30,
+                  end: 40,
+                  color: InsightsColors.bmiObesityZone,
+                ),
+              ],
+            ),
+            trackballBehavior: buildInsightsTrackball(),
+            series: <CartesianSeries<InsightsPoint, String>>[
+              SplineAreaSeries<InsightsPoint, String>(
+                name: s.insights_tab_bmi,
+                dataSource: points,
+                xValueMapper: (point, _) => point.label,
+                yValueMapper: (point, _) => point.value,
+                borderColor: InsightsColors.blue,
+                borderWidth: 3,
+                gradient: buildInsightsAreaGradient(InsightsColors.blue),
+                markerSettings: buildInsightsMarker(InsightsColors.blue),
+              ),
+            ],
+          ),
+        ),
+        if (model.hint.isNotEmpty) ...[
+          const SizedBox(height: 8),
+          Text(
+            model.hint,
+            key: const Key('insights_bmi_hint'),
+            style: const TextStyle(
+              fontSize: 13,
+              color: InsightsColors.subtitle,
+            ),
+          ),
+        ],
+      ],
+    );
+  }
+}