fix: owner event bookings list and paid plan durations from plan_to_months.

Fixes EventHub/EventHubBack#51
Fixes EventHub/EventHubBack#52

Co-authored-by: Cursor <cursoragent@cursor.com>

src/core/core_subscription.erl

@@ -8,35 +8,27 @@
 -export([count_subscriptions_by_plan/0, count_subscriptions_by_status/0,
   count_trial_subscriptions/0, get_ending_paid_subscriptions/1]).
 
--define(TRIAL_DAYS, 30).
-
 %%%-------------------------------------------------------------------
 %%% @doc Создание подписки.
-%%% `TrialUsed` – `true`, если подписка платная; `false` для пробного периода.
+%%% `TrialUsed` – флаг (использован ли trial); на длительность не влияет.
+%%% Длительность всегда считается из `Plan` через `plan_to_months/1`.
 %%% Все поля записи инициализированы, `undefined` не возникает.
 %%% @end
 %%%-------------------------------------------------------------------
--spec create(UserId :: binary(), Plan :: monthly | quarterly | biannual | annual,
+-spec create(UserId :: binary(), Plan :: monthly | quarterly | biannual | annual | trial,
     TrialUsed :: boolean()) -> {ok, #subscription{}} | {error, term()}.
 create(UserId, Plan, TrialUsed) ->
   Id = infra_utils:generate_id(16),
   Now = calendar:universal_time(),
-  {StartDate, EndDate} = case TrialUsed of
-                           true ->
-                             DurationMonths = plan_to_months(Plan),
-                             End = add_months(Now, DurationMonths),
-                             {Now, End};
-                           false ->
-                             End = add_days(Now, ?TRIAL_DAYS),
-                             {Now, End}
-                         end,
+  DurationMonths = plan_to_months(Plan),
+  EndDate = add_months(Now, DurationMonths),
   Subscription = #subscription{
     id          = Id,
     user_id     = UserId,
     plan        = Plan,
     status      = active,
     trial_used  = TrialUsed,
-    started_at  = StartDate,
+    started_at  = Now,
     expires_at  = EndDate,
     created_at  = Now,
     updated_at  = Now
@@ -167,11 +159,6 @@ add_months(DateTime, Months) ->
   NewDays = Days + (Months * 30),
   calendar:gregorian_seconds_to_datetime(NewDays * 86400).
 
--spec add_days(calendar:datetime(), pos_integer()) -> calendar:datetime().
-add_days(DateTime, Days) ->
-  Seconds = calendar:datetime_to_gregorian_seconds(DateTime),
-  calendar:gregorian_seconds_to_datetime(Seconds + (Days * 86400)).
-
 %%%===================================================================
 %%% Новые обёртки для админки
 %%%===================================================================