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>

pubspec.yaml

@@ -13,11 +13,14 @@ dependencies:
   drift_flutter: ^0.2.8
   flutter:
     sdk: flutter
+  flutter_local_notifications: ^20.1.0
   flutter_localizations:
     sdk: flutter
+  flutter_timezone: ^5.1.1
   intl: ^0.20.2
   provider: ^6.1.5+1
   shared_preferences: ^2.5.3
+  timezone: ^0.10.1
   uuid: ^4.6.0
   wakelock_plus: ^1.4.0