chore: import upstream snapshot with attribution

tests/integrations/test_home_isolation.py

@@ -0,0 +1,25 @@
+"""Regression tests for integration-test environment isolation."""
+
+from __future__ import annotations
+
+import os
+from pathlib import Path
+
+
+def test_integration_tests_use_tmp_home(tmp_path: Path) -> None:
+    home = tmp_path / "home"
+
+    assert Path(os.environ["HOME"]) == home
+    assert Path(os.environ["USERPROFILE"]) == home
+    assert Path(os.environ["XDG_CACHE_HOME"]) == home / ".cache"
+    assert Path(os.environ["XDG_CONFIG_HOME"]) == home / ".config"
+    assert Path(os.environ["XDG_DATA_HOME"]) == home / ".local" / "share"
+
+    # Most integrations resolve the user home via Path.home() (e.g. Hermes,
+    # catalog), so the isolation has to reach that API, not just the env vars.
+    assert Path.home() == home
+
+    assert home.is_dir()
+    assert (home / ".cache").is_dir()
+    assert (home / ".config").is_dir()
+    assert (home / ".local" / "share").is_dir()