feat: disable webhook/websocket by default

lib/wanderer_app_web/controllers/plugs/check_websocket_disabled.ex

@@ -0,0 +1,15 @@
+defmodule WandererAppWeb.Plugs.CheckWebsocketDisabled do
+  import Plug.Conn
+
+  def init(opts), do: opts
+
+  def call(conn, _opts) do
+    if not WandererApp.Env.websocket_events_enabled?() do
+      conn
+      |> send_resp(403, "WebSocket events are disabled")
+      |> halt()
+    else
+      conn
+    end
+  end
+end