Add android.notification.channelId to the 4 senders not covered by the earlier batch:
scheduledOutcomesReminder + dailyQuestionReminder + reengagement -> 'reminders';
sendGentleReminderCallable -> 'partner_activity'. Completes E-OBS so backgrounded pushes land on
their proper channels (importance/sound + per-category toggle) instead of fcm_fallback. tsc green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>