refactor(types): drop guards and clauses that can never succeed

lib/mv_web/live/membership_fee_settings_live.ex

@@ -464,7 +464,6 @@ defmodule MvWeb.MembershipFeeSettingsLive do
     Enum.map_join(error.errors, ", ", fn e -> e.message end)
   end
 
-  defp format_error(error) when is_binary(error), do: error
   defp format_error(_error), do: gettext("An error occurred")
 
   defp assign_form(%{assigns: %{settings: settings}} = socket) do

lib/mv_web/live/membership_fee_type_live/index.ex

@@ -214,7 +214,6 @@ defmodule MvWeb.MembershipFeeTypeLive.Index do
     Enum.map_join(error.errors, ", ", fn e -> e.message end)
   end
 
-  defp format_error(error) when is_binary(error), do: error
   defp format_error(_error), do: gettext("An error occurred")
 
   # Info card explaining the membership fee type concept

lib/mv_web/live/user_live/form.ex

@@ -922,7 +922,7 @@ defmodule MvWeb.UserLive.Form do
   end
 
   # Extract user-friendly error message from Ash.Error
-  @spec extract_error_message(any()) :: String.t()
+  @spec extract_error_message(Ash.Error.t()) :: String.t()
   defp extract_error_message(%Ash.Error.Invalid{errors: errors}) when is_list(errors) do
     # Take first error and extract message
     case List.first(errors) do
@@ -932,6 +932,5 @@ defmodule MvWeb.UserLive.Form do
     end
   end
 
-  defp extract_error_message(error) when is_binary(error), do: error
   defp extract_error_message(_), do: gettext("Unknown error")
 end