feat(engagement): localize limits and streaks

Use reported user timezones for daily response limits, expose couple streak state and reminders, and improve swipe and live-drawing synchronization with focused tests and documentation.

apps/api/test/profile-settings.routes.test.ts

@@ -20,6 +20,7 @@ const preferences = {
   pack_changes_enabled: true,
   new_packs_enabled: true,
   streak_milestones_enabled: true,
+  streak_reminders_enabled: true,
   weekly_summary_enabled: true,
   unpaired_reminders_enabled: true,
   catchup_reminders_enabled: true,