iter 23.1.2: load_workspace auto-injects prelude module

crates/ail/tests/e2e.rs

@@ -846,7 +846,9 @@ fn workspace_lists_imported_modules() {
     );
 
     let modules = v["modules"].as_array().expect("modules must be array");
-    assert_eq!(modules.len(), 2, "expected 2 modules: {stdout}");
+    // Iter 23.1: the loader auto-injects the `prelude` module, so
+    // the count is the user's two modules plus prelude.
+    assert_eq!(modules.len(), 3, "expected 3 modules: {stdout}");
 
     let names: Vec<&str> = modules
         .iter()
@@ -854,6 +856,7 @@ fn workspace_lists_imported_modules() {
         .collect();
     assert!(names.contains(&"ws_main"), "ws_main missing: {names:?}");
     assert!(names.contains(&"ws_lib"), "ws_lib missing: {names:?}");
+    assert!(names.contains(&"prelude"), "prelude missing: {names:?}");
 }
 
 /// Guards Iter 5b: `ail check examples/ws_main.ail.json --json` must