Auto-validate architecture guard module inventory

Co-authored-by: Shri Sukhani <shrisukhani@users.noreply.github.com>

Author: cursoragent

tests/test_architecture_marker_usage.py

@@ -22,6 +22,7 @@
     "tests/test_polling_loop_usage.py",
     "tests/test_core_type_helper_usage.py",
     "tests/test_contributing_architecture_guard_listing.py",
+    "tests/test_readme_examples_listing.py",
     "tests/test_examples_syntax.py",
     "tests/test_docs_python3_commands.py",
     "tests/test_example_sync_async_parity.py",
@@ -35,3 +36,14 @@ def test_architecture_guard_modules_are_marked():
     for module_path in ARCHITECTURE_GUARD_MODULES:
         module_text = Path(module_path).read_text(encoding="utf-8")
         assert "pytestmark = pytest.mark.architecture" in module_text
+
+
+def test_architecture_guard_module_list_stays_in_sync_with_marker_files():
+    discovered_modules: list[str] = []
+    for module_path in sorted(Path("tests").glob("test_*.py")):
+        module_text = module_path.read_text(encoding="utf-8")
+        if "pytestmark = pytest.mark.architecture" not in module_text:
+            continue
+        discovered_modules.append(module_path.as_posix())
+
+    assert sorted(ARCHITECTURE_GUARD_MODULES) == discovered_modules