fix(portal): renew session on sign in (#10616)

When signing in, it's a good idea to clear any previous session cookie
and regenerate it, preventing the chance that any unchecked data in a
possible-fixated session cookie is used.

elixir/apps/web/lib/web/auth.ex

@@ -49,7 +49,9 @@ defmodule Web.Auth do
 
     sessions = Enum.take(sessions ++ [session], -1 * @remember_last_sessions)
 
-    Plug.Conn.put_session(conn, :sessions, sessions)
+    conn
+    |> renew_session()
+    |> Plug.Conn.put_session(:sessions, sessions)
   end
 
   defp delete_account_session(conn, context_type, account_id) do