Stage 5: History, the shared daily Streak and Reminders

- Streak computed from all complete Sessions: Grace Hour (00:00-01:00
  counts for yesterday unless it is done), a Freeze per 7 Streak Days
  (max 2) spent automatically on a missed day (ADR 0006)
- Top bar flame (grey until today is done) opening a panel with current
  and longest Streak, Freezes and a month calendar; 'Day N of your
  streak' on a fresh summary
- History per Mode grouped by day, reopening each summary
- Two adjustable Reminders (19:00, 22:30) scheduled 14 days ahead with
  flutter_local_notifications, none on a done day; permission asked
  after the first complete Session or from Settings
- Settings: Reminders, the Player chime, exercise credits

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/history/session_repository_test.dart

@@ -55,4 +55,12 @@ void main() {
 
     expect(workout.map((s) => s.endedAt.day), [29, 28]);
   });
+
+  test('the Streak sees complete Sessions of both Modes only', () async {
+    await sessions.save(result(Mode.workout, DateTime(2026, 10, 28)));
+    await sessions.save(result(Mode.stretching, DateTime(2026, 10, 29)));
+    await sessions.save(result(Mode.stretching, DateTime(2026, 10, 30), complete: false));
+
+    expect(await sessions.completeEndTimes(), unorderedEquals([DateTime(2026, 10, 28), DateTime(2026, 10, 29)]));
+  });
 }