Improve skills and document updates

tests/test_plugin_helper.py

@@ -793,6 +793,20 @@ install_strategy = "dll-to-plugins"
             )
             self.assertTrue(plan_path.exists())
             self.assertEqual(plan["changes"][0]["target"], "Plugins/Example.dll")
+            self.assertEqual(plan["unchanged"], [])
+
+            apply_plan(plan, state)
+            same_plan, _same_path = create_plan(
+                instance="1.40.8",
+                instance_path=instance,
+                beat_saber_version="1.40.8",
+                registry=registry,
+                lockfile=lockfile,
+                state_root=state,
+                repo_root=work,
+            )
+            self.assertEqual(same_plan["changes"], [])
+            self.assertEqual(same_plan["unchanged"][0]["target"], "Plugins/Example.dll")
 
             result = apply_plan(plan, state)
             self.assertEqual(len(result["applied"]), 1)