fix: defer expiry reminders for trial and bonus subscriptions

Trial and registration/referral-bonus subscriptions usually last only a
few days, so the multi-day ending-soon reminders fired almost the moment
they were granted and needlessly alarmed newcomers.

Track this with a new subscription flag (suppress_early_expiry_notifications,
migration 0035): trial activation, referral welcome bonus and inviter bonus
grants set it, while a real paid purchase clears it on upsert. While set, the
notification worker skips the day-before stages but still sends the
hours-before reminder and the expiry/after-expiry notices, so users are
warned shortly before access ends. Once they pay for a full subscription the
complete reminder spectrum resumes.

backend/bot/services/subscription_service_impl/lifecycle.py

@@ -641,6 +641,9 @@ class SubscriptionLifecycleMixin:
             "traffic_limit_bytes": traffic_limit_bytes,
             "provider": provider,
             "skip_notifications": False,
+            # A real payment restores the full reminder spectrum, clearing any
+            # trial/bonus suppression carried over on this panel subscription.
+            "suppress_early_expiry_notifications": False,
             "auto_renew_enabled": auto_renew_should_enable,
             "tariff_key": tariff.key if tariff else None,
             "tier_baseline_bytes": tier_baseline_bytes,
@@ -776,6 +779,9 @@ class SubscriptionLifecycleMixin:
                 "status_from_panel": "ACTIVE_BONUS",
                 "traffic_limit_bytes": traffic_limit,
                 "auto_renew_enabled": False,
+                # Registration/referral bonus grants are short-lived, like a
+                # trial: only warn a few hours before they end, not days ahead.
+                "suppress_early_expiry_notifications": True,
             }
             await subscription_dal.deactivate_other_active_subscriptions(
                 session, panel_uuid, panel_sub_uuid

backend/bot/services/subscription_service_impl/trial.py

@@ -63,6 +63,8 @@ class TrialSubscriptionMixin:
             "traffic_limit_bytes": self.settings.trial_traffic_limit_bytes,
             "auto_renew_enabled": False,
             "provider": "trial",
+            # Short trial: only warn a few hours before it ends, not days ahead.
+            "suppress_early_expiry_notifications": True,
         }
         try:
             await subscription_dal.upsert_subscription(session, trial_sub_data)