feat(train): Home opens on this week, its totals and its seven days (ADR 0030, D60)

The week's time, distance and workouts above Home's list, and a strip of
its days, each as tall as the time trained on it, starting on the day the
person's language starts weeks on. Home's empty hint points to the Record
tab, where its button had gone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/train/halkyon_train_flutter/test/feature/workout/week_summary_test.dart

@@ -0,0 +1,112 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:halkyon_train_flutter/src/feature/workout/data/week_summary.dart';
+import 'package:halkyon_train_flutter/src/feature/workout/model/workout.dart';
+
+/// The week Home sums up above the workouts (ADR 0030, D60): from the day
+/// the person's weeks start on, in their own time, each workout counted on
+/// the day it started.
+void main() {
+  // Saturday, 31 October 2026, in the afternoon, local time.
+  final now = DateTime(2026, 10, 31, 15);
+
+  WorkoutContent workout(
+    DateTime start, {
+    Duration length = const Duration(hours: 1),
+    Duration? moving,
+    int? metres,
+  }) => WorkoutContent(
+    activity: Activity.running,
+    startedAt: start.toUtc(),
+    endedAt: start.add(length).toUtc(),
+    movingTime: moving,
+    distanceMetres: metres,
+  );
+
+  test('a week starting on Monday sums the workouts from Monday on', () {
+    final week = weekSummary(
+      [
+        workout(
+          DateTime(2026, 10, 26, 7),
+          moving: const Duration(minutes: 40),
+          metres: 8000,
+        ),
+        workout(
+          DateTime(2026, 10, 31, 9),
+          moving: const Duration(minutes: 20),
+          metres: 4500,
+        ),
+        // Sunday before: last week.
+        workout(DateTime(2026, 10, 25, 23, 30), metres: 10000),
+      ],
+      now: now,
+      firstDay: DateTime.monday,
+    );
+
+    expect(week.start, DateTime(2026, 10, 26));
+    expect(week.count, 2);
+    expect(week.time, const Duration(hours: 1));
+    expect(week.metres, 12500);
+    expect(week.days.map((d) => d.weekday), [1, 2, 3, 4, 5, 6, 7]);
+    expect(week.days.map((d) => d.time.inMinutes), [40, 0, 0, 0, 0, 20, 0]);
+    expect(week.today, 5);
+  });
+
+  test('a week starting on Sunday takes in the Sunday before', () {
+    final week = weekSummary(
+      [
+        workout(DateTime(2026, 10, 25, 23, 30)),
+      ],
+      now: now,
+      firstDay: DateTime.sunday,
+    );
+
+    expect(week.start, DateTime(2026, 10, 25));
+    expect(week.days.first.weekday, DateTime.sunday);
+    expect(week.days.first.time, const Duration(hours: 1));
+    expect(week.today, 6);
+  });
+
+  test('without its moving time a workout counts from start to end; '
+      'without a distance, none', () {
+    final week = weekSummary(
+      [
+        workout(
+          DateTime(2026, 10, 27, 18),
+          length: const Duration(minutes: 45),
+        ),
+      ],
+      now: now,
+      firstDay: DateTime.monday,
+    );
+
+    expect(week.time, const Duration(minutes: 45));
+    expect(week.metres, 0);
+    expect(week.count, 1);
+  });
+
+  test('a week without workouts is all naught', () {
+    final week = weekSummary(const [], now: now, firstDay: DateTime.monday);
+
+    expect(week.count, 0);
+    expect(week.time, Duration.zero);
+    expect(week.days, hasLength(7));
+    expect(week.longestDay, Duration.zero);
+  });
+
+  test('the longest day scales the strip', () {
+    final week = weekSummary(
+      [
+        workout(DateTime(2026, 10, 26, 7), moving: const Duration(minutes: 30)),
+        workout(
+          DateTime(2026, 10, 26, 18),
+          moving: const Duration(minutes: 30),
+        ),
+        workout(DateTime(2026, 10, 28, 7), moving: const Duration(minutes: 20)),
+      ],
+      now: now,
+      firstDay: DateTime.monday,
+    );
+
+    expect(week.longestDay, const Duration(hours: 1));
+  });
+}