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

test/unit/logic_booking_tests.erl

@@ -3,7 +3,7 @@
 -include("records.hrl").
 
 -define(TABLES, [user, calendar, event, booking, admin, subscription, calendar_specialist,
-  recurrence_exception]).
+  recurrence_exception, notification]).
 
 setup() ->
   eh_test_support:start_mnesia(),
@@ -54,7 +54,10 @@ logic_booking_test_() ->
       {"Past pending excluded from booking requests", fun test_past_pending_excluded_from_requests/0},
       {"Past pending confirm denied", fun test_past_pending_confirm_denied/0},
       {"Future pending still confirmable", fun test_future_pending_still_confirmable/0},
-      {"Process timeout expires past pending", fun test_process_timeout_expires_past/0}
+      {"Process timeout expires past pending", fun test_process_timeout_expires_past/0},
+      {"Reminder sends once within lead window", fun test_reminder_within_window/0},
+      {"Reminder skipped outside lead window", fun test_reminder_outside_window/0},
+      {"Reminder skipped for pending", fun test_reminder_skips_pending/0}
     ]}.
 
 %% Вспомогательные функции
@@ -509,3 +512,89 @@ test_process_timeout_expires_past() ->
   ok = logic_booking:process_timeout_bookings(),
   {ok, Stored} = core_booking:get_by_id(Booking#booking.id),
   ?assertEqual(expired, Stored#booking.status).
+
+hours_from_now(Hours) ->
+  Sec = calendar:datetime_to_gregorian_seconds(calendar:universal_time())
+        + Hours * 3600,
+  calendar:gregorian_seconds_to_datetime(Sec).
+
+test_reminder_within_window() ->
+  application:set_env(eventhub, reminder_lead_hours, 24),
+  Self = self(),
+  application:set_env(eventhub, smtp_host, "smtp.test"),
+  application:set_env(eventhub, smtp_deliver,
+    fun(_From, To, Raw, _Opts) ->
+      Self ! {smtp, To, Raw},
+      {ok, mock}
+    end),
+  OwnerId = create_test_user(user),
+  ParticipantId = create_test_user(user),
+  CalendarId = create_test_calendar(OwnerId, auto),
+  EventId = create_test_event_at(CalendarId, hours_from_now(2)),
+  {ok, Booking} = logic_booking:create_booking(ParticipantId, EventId),
+  ?assertEqual(confirmed, Booking#booking.status),
+  ?assertEqual(false, Booking#booking.reminder_sent),
+  ok = logic_booking:process_reminders(),
+  receive
+    {smtp, To, Raw} ->
+      ?assertEqual(<<ParticipantId/binary, "@test.com">>, To),
+      ?assert(binary:match(Raw, <<"CalenTIQ">>) =/= nomatch),
+      ?assert(binary:match(Raw, <<"/c/", CalendarId/binary, "/e/", EventId/binary>>)
+              =/= nomatch)
+  after 1000 ->
+    error(timeout_reminder_email)
+  end,
+  {ok, Stored} = core_booking:get_by_id(Booking#booking.id),
+  ?assertEqual(true, Stored#booking.reminder_sent),
+  Notifs = core_notification:list_by_user(ParticipantId),
+  ?assert(lists:any(fun(#notification{type = event_reminder}) -> true; (_) -> false end,
+                    Notifs)),
+  %% second pass: no duplicate email
+  ok = logic_booking:process_reminders(),
+  receive
+    {smtp, _, _} -> error(duplicate_reminder)
+  after 200 ->
+    ok
+  end,
+  application:unset_env(eventhub, smtp_host),
+  application:unset_env(eventhub, smtp_deliver),
+  application:unset_env(eventhub, reminder_lead_hours).
+
+test_reminder_outside_window() ->
+  application:set_env(eventhub, reminder_lead_hours, 24),
+  Self = self(),
+  application:set_env(eventhub, smtp_host, "smtp.test"),
+  application:set_env(eventhub, smtp_deliver,
+    fun(_From, To, Raw, _Opts) ->
+      Self ! {smtp, To, Raw},
+      {ok, mock}
+    end),
+  OwnerId = create_test_user(user),
+  ParticipantId = create_test_user(user),
+  CalendarId = create_test_calendar(OwnerId, auto),
+  EventId = create_test_event_at(CalendarId, hours_from_now(48)),
+  {ok, Booking} = logic_booking:create_booking(ParticipantId, EventId),
+  ok = logic_booking:process_reminders(),
+  receive
+    {smtp, _, _} -> error(unexpected_reminder)
+  after 200 ->
+    ok
+  end,
+  {ok, Stored} = core_booking:get_by_id(Booking#booking.id),
+  ?assertEqual(false, Stored#booking.reminder_sent),
+  application:unset_env(eventhub, smtp_host),
+  application:unset_env(eventhub, smtp_deliver),
+  application:unset_env(eventhub, reminder_lead_hours).
+
+test_reminder_skips_pending() ->
+  application:set_env(eventhub, reminder_lead_hours, 24),
+  OwnerId = create_test_user(user),
+  ParticipantId = create_test_user(user),
+  CalendarId = create_test_calendar(OwnerId, manual),
+  EventId = create_test_event_at(CalendarId, hours_from_now(2)),
+  {ok, Booking} = logic_booking:create_booking(ParticipantId, EventId),
+  ?assertEqual(pending, Booking#booking.status),
+  ok = logic_booking:process_reminders(),
+  {ok, Stored} = core_booking:get_by_id(Booking#booking.id),
+  ?assertEqual(false, Stored#booking.reminder_sent),
+  application:unset_env(eventhub, reminder_lead_hours).