refactor: improve code quality in ApiTokens.update_last_used

Reduced nesting and extracted helper functions to address credo
warnings. The logic remains the same:
- Test environment: synchronous update
- Production: async Task with sandbox support

Fixes credo warnings:
- Reduced function body nesting (was 3, now 2)
- Extracted spawn_async_update and helper functions

lib/towerops/api_tokens.ex

@@ -172,28 +172,37 @@ defmodule Towerops.ApiTokens do
   end
 
   defp update_last_used(token) do
+    timestamp = DateTime.truncate(DateTime.utc_now(), :second)
+
     # In test mode, update synchronously to avoid ownership issues
     # In production, use Task.start to avoid blocking the request
-    if Application.get_env(:towerops, :env) == :test do
-      token
-      |> Ecto.Changeset.change(last_used_at: DateTime.truncate(DateTime.utc_now(), :second))
-      |> Repo.update()
-    else
-      # Get the parent process PID before spawning the task
-      parent = self()
+    case Application.get_env(:towerops, :env) do
+      :test ->
+        update_token_timestamp(token, timestamp)
 
-      # Use Task.start to avoid blocking the request
-      # We don't care if this fails
-      Task.start(fn ->
-        # Allow the task to access the database in test mode
-        if Application.get_env(:towerops, :sql_sandbox) do
-          Ecto.Adapters.SQL.Sandbox.allow(Repo, parent, self())
-        end
+      _ ->
+        spawn_async_update(token, timestamp)
+    end
+  end
 
-        token
-        |> Ecto.Changeset.change(last_used_at: DateTime.truncate(DateTime.utc_now(), :second))
-        |> Repo.update()
-      end)
+  defp update_token_timestamp(token, timestamp) do
+    token
+    |> Ecto.Changeset.change(last_used_at: timestamp)
+    |> Repo.update()
+  end
+
+  defp spawn_async_update(token, timestamp) do
+    parent = self()
+
+    Task.start(fn ->
+      maybe_allow_sandbox(parent)
+      update_token_timestamp(token, timestamp)
+    end)
+  end
+
+  defp maybe_allow_sandbox(parent) do
+    if Application.get_env(:towerops, :sql_sandbox) do
+      Ecto.Adapters.SQL.Sandbox.allow(Repo, parent, self())
     end
   end
 end