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>

future_ideas.md

@@ -14,4 +14,5 @@ Things deliberately left out of v1.
 - Translations (v1 is English only)
 - Light/dark setting per Mode (v1 has a fixed look per Mode)
 - Full-screen Streak celebrations and milestones (7/30/100/365 days)
+- Exact-time Reminders (needs Android's exact-alarm permission)
 - Mixed Plans that combine Stretching and Workout (e.g. warm-up, workout, cool-down)