[Bash] Fix Windows cookbook background tasks (#676)

* Fix Windows cookbook background tasks

* Add Windows Cookbook reliability follow-ups

tests/test_platform_compat.py

@@ -1,6 +1,14 @@
 """Regression tests for cross-platform helper behavior."""
 
-from core import platform_compat
+import importlib.util
+from pathlib import Path
+
+
+_MODULE_PATH = Path(__file__).resolve().parents[1] / "core" / "platform_compat.py"
+_SPEC = importlib.util.spec_from_file_location("platform_compat_under_test", _MODULE_PATH)
+platform_compat = importlib.util.module_from_spec(_SPEC)
+assert _SPEC and _SPEC.loader
+_SPEC.loader.exec_module(platform_compat)
 
 
 def _reset_bash_cache(monkeypatch):
@@ -35,3 +43,19 @@ def test_find_bash_checks_local_app_data_git_install(monkeypatch):
     monkeypatch.setattr(platform_compat.os.path, "exists", lambda path: path == expected)
 
     assert platform_compat.find_bash() == expected
+
+
+def test_find_bash_skips_windows_wsl_stub(monkeypatch):
+    _reset_bash_cache(monkeypatch)
+    monkeypatch.setattr(platform_compat, "IS_WINDOWS", True)
+
+    stub = r"C:\WINDOWS\system32\bash.exe"
+    expected = r"C:\Program Files\Git\bin\bash.exe"
+    monkeypatch.setattr(
+        platform_compat.shutil,
+        "which",
+        lambda name: stub if name == "bash" else None,
+    )
+    monkeypatch.setattr(platform_compat.os.path, "exists", lambda path: path == expected)
+
+    assert platform_compat.find_bash() == expected