feat(email): send booking reminders before event start.

Job process_reminders in subscription_worker; REMINDER_LEAD_HOURS window;
CalenTIQ email + in-app event_reminder; idempotent reminder_sent.
Refs EventHub/EventHubBack#70

docker/.env.example

@@ -28,4 +28,6 @@ SMTP_PASS=
 SMTP_FROM=noreply@calentiq.com
 SMTP_TLS=if_available
 PUBLIC_APP_URL=https://stage.calentiq.com
+# Окно напоминаний о booking (часы до старта; Back#70)
+REMINDER_LEAD_HOURS=24
 

docker/docker-compose.stage.yml

@@ -48,6 +48,7 @@ services:
       - SMTP_FROM=${SMTP_FROM:-noreply@calentiq.com}
       - SMTP_TLS=${SMTP_TLS:-if_available}
       - PUBLIC_APP_URL=${PUBLIC_APP_URL:-https://stage.calentiq.com}
+      - REMINDER_LEAD_HOURS=${REMINDER_LEAD_HOURS:-24}
     networks:
       eventhub-net:
         aliases: