fix: tolerate existing eventhub_counters ETS on infra_mnesia restart

Supervisor restarts after mnesia_stopped crashed on ets:new already_exists.

src/infra/infra_mnesia.erl

@@ -36,7 +36,11 @@
 
 start_link() ->
   % Счётчики для метрик (сессии, ws-соединения)
-  ets:new(eventhub_counters, [named_table, public, set, {write_concurrency, true}]),
+  case ets:info(eventhub_counters) of
+    undefined ->
+      ets:new(eventhub_counters, [named_table, public, set, {write_concurrency, true}]);
+    _ -> ok
+  end,
   gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
 
 init_tables() ->