refactor(types): reconcile @specs with their success typings

lib/mv/membership_fees/cycle_generator.ex

@@ -1,4 +1,11 @@
 defmodule Mv.MembershipFees.CycleGenerator do
+  @typedoc "Aggregate counts returned by a batch cycle-generation run."
+  @type results_summary :: %{
+          success: non_neg_integer(),
+          failed: non_neg_integer(),
+          total: non_neg_integer()
+        }
+
   @moduledoc """
   Module for generating membership fee cycles for members.
 
@@ -159,7 +166,8 @@ defmodule Mv.MembershipFees.CycleGenerator do
     - `{:error, reason}` - Error with reason
 
   """
-  @spec generate_cycles_for_all_members(keyword()) :: {:ok, map()} | {:error, term()}
+  @spec generate_cycles_for_all_members(keyword()) ::
+          {:ok, results_summary()} | {:error, Ash.Error.t()}
   def generate_cycles_for_all_members(opts \\ []) do
     today = Keyword.get(opts, :today, Date.utc_today())
     batch_size = Keyword.get(opts, :batch_size, 10)