refactor: reduce nesting depth in regenerate_cycles_on_type_change

Split the function into smaller, focused functions to reduce nesting depth

lib/membership/member.ex

@@ -705,7 +705,6 @@ defmodule Mv.Membership.Member do
   # Deletes future unpaid cycles and regenerates them with the new type/amount
   # Uses advisory lock to prevent concurrent modifications
   defp regenerate_cycles_on_type_change(member) do
-    require Ash.Query
     alias Mv.Repo
 
     today = Date.utc_today()
@@ -714,11 +713,24 @@ defmodule Mv.Membership.Member do
     # Use advisory lock to prevent concurrent deletion and regeneration
     # This ensures atomicity when multiple updates happen simultaneously
     if Repo.in_transaction?() do
+      regenerate_cycles_in_transaction(member, today, lock_key)
+    else
+      regenerate_cycles_new_transaction(member, today, lock_key)
+    end
+  end
+
   # Already in transaction: use advisory lock directly
+  defp regenerate_cycles_in_transaction(member, today, lock_key) do
+    alias Mv.Repo
+
     Ecto.Adapters.SQL.query!(Repo, "SELECT pg_advisory_xact_lock($1)", [lock_key])
     do_regenerate_cycles_on_type_change(member, today)
-    else
+  end
+
   # Not in transaction: start new transaction with advisory lock
+  defp regenerate_cycles_new_transaction(member, today, lock_key) do
+    alias Mv.Repo
+
     Repo.transaction(fn ->
       Ecto.Adapters.SQL.query!(Repo, "SELECT pg_advisory_xact_lock($1)", [lock_key])
 
@@ -727,13 +739,13 @@ defmodule Mv.Membership.Member do
         {:error, reason} -> Repo.rollback(reason)
       end
     end)
-      |> case do
+    |> handle_transaction_result()
-        {:ok, result} -> result
-        {:error, reason} -> {:error, reason}
-      end
-    end
   end
 
+  # Handle transaction result
+  defp handle_transaction_result({:ok, result}), do: result
+  defp handle_transaction_result({:error, reason}), do: {:error, reason}
+
   # Performs the actual cycle deletion and regeneration
   defp do_regenerate_cycles_on_type_change(member, today) do
     require Ash.Query