refactor(types): remove dead catch-all clauses unreachable per success typing

lib/mv/config.ex

@@ -207,8 +207,6 @@ defmodule Mv.Config do
     end
   end
 
-  defp derive_app_url_from_api_url(_), do: nil
-
   @doc """
   Returns true if Vereinfacht is fully configured (URL, API key, and club ID all set).
   """
@@ -251,7 +249,6 @@ defmodule Mv.Config do
     case System.get_env(key) do
       nil -> false
       v when is_binary(v) -> String.trim(v) != ""
-      _ -> false
     end
   end
 
@@ -270,9 +267,6 @@ defmodule Mv.Config do
       value when is_binary(value) ->
         v = String.trim(value) |> String.downcase()
         v in ["true", "1", "yes"]
-
-      _ ->
-        false
     end
   end
 
@@ -328,7 +322,6 @@ defmodule Mv.Config do
 
   defp present?(nil), do: false
   defp present?(s) when is_binary(s), do: String.trim(s) != ""
-  defp present?(_), do: false
 
   # ---------------------------------------------------------------------------
   # OIDC authentication