fix(tests): add _patch_managed_uv autouse fixture to uv-dependent test files

Production code now uses ensure_uv()/update_managed_uv() from
managed_uv.py instead of shutil.which("uv") directly. Tests that
patched shutil.which to control uv availability no longer controlled
the actual code path, causing CI failures.

Add an autouse _patch_managed_uv fixture to test_update_autostash.py
and test_uv_tool_update.py (matching the existing fixture in
test_cmd_update.py). The fixture makes managed_uv functions delegate
to shutil.which so existing test patches flow through naturally.

tests/hermes_cli/test_update_autostash.py

@@ -1,6 +1,7 @@
 from pathlib import Path
 from subprocess import CalledProcessError
 from types import SimpleNamespace
+from unittest.mock import patch
 
 import pytest
 
@@ -8,6 +9,41 @@ from hermes_cli import config as hermes_config
 from hermes_cli import main as hermes_main
 
 
+# ---------------------------------------------------------------------------
+# Managed-uv compatibility for tests that patch shutil.which
+# ---------------------------------------------------------------------------
+# The production code now uses ``ensure_uv()`` / ``update_managed_uv()``
+# instead of ``shutil.which("uv")``.  Many tests in this file patch
+# ``shutil.which`` to control whether uv is "available" — these autouse
+# fixtures make the managed_uv functions delegate to the patched
+# ``shutil.which`` so the existing test setup keeps working without
+# per-test changes.
+@pytest.fixture(autouse=True)
+def _patch_managed_uv(request):
+    """Make managed_uv helpers follow shutil.which mocking in tests."""
+    import shutil
+
+    # resolve_uv delegates to shutil.which("uv") so that test patches
+    # on shutil.which flow through naturally.
+    def _fake_resolve_uv():
+        return shutil.which("uv")
+
+    def _fake_ensure_uv():
+        path = shutil.which("uv")
+        return (path, False)  # never freshly bootstrapped in tests
+
+    def _fake_update_managed_uv():
+        return None  # never actually self-update in tests
+
+    def _fake_rebuild_venv(*args, **kwargs):
+        return True  # no-op in tests
+
+    with patch("hermes_cli.managed_uv.resolve_uv", side_effect=_fake_resolve_uv), \
+         patch("hermes_cli.managed_uv.ensure_uv", side_effect=_fake_ensure_uv), \
+         patch("hermes_cli.managed_uv.update_managed_uv", side_effect=_fake_update_managed_uv), \
+         patch("hermes_cli.managed_uv.rebuild_venv", side_effect=_fake_rebuild_venv):
+        yield
+
 def test_stash_local_changes_if_needed_returns_none_when_tree_clean(monkeypatch, tmp_path):
     calls = []
 

tests/hermes_cli/test_uv_tool_update.py

@@ -20,6 +20,42 @@ from unittest.mock import patch
 import pytest
 
 
+# ---------------------------------------------------------------------------
+# Managed-uv compatibility for tests that patch shutil.which
+# ---------------------------------------------------------------------------
+# The production code now uses ``ensure_uv()`` / ``update_managed_uv()``
+# instead of ``shutil.which("uv")``.  Many tests in this file patch
+# ``shutil.which`` to control whether uv is "available" — these autouse
+# fixtures make the managed_uv functions delegate to the patched
+# ``shutil.which`` so the existing test setup keeps working without
+# per-test changes.
+@pytest.fixture(autouse=True)
+def _patch_managed_uv(request):
+    """Make managed_uv helpers follow shutil.which mocking in tests."""
+    import shutil
+
+    # resolve_uv delegates to shutil.which("uv") so that test patches
+    # on shutil.which flow through naturally.
+    def _fake_resolve_uv():
+        return shutil.which("uv")
+
+    def _fake_ensure_uv():
+        path = shutil.which("uv")
+        return (path, False)  # never freshly bootstrapped in tests
+
+    def _fake_update_managed_uv():
+        return None  # never actually self-update in tests
+
+    def _fake_rebuild_venv(*args, **kwargs):
+        return True  # no-op in tests
+
+    with patch("hermes_cli.managed_uv.resolve_uv", side_effect=_fake_resolve_uv), \
+         patch("hermes_cli.managed_uv.ensure_uv", side_effect=_fake_ensure_uv), \
+         patch("hermes_cli.managed_uv.update_managed_uv", side_effect=_fake_update_managed_uv), \
+         patch("hermes_cli.managed_uv.rebuild_venv", side_effect=_fake_rebuild_venv):
+        yield
+
+
 # ---------------------------------------------------------------------------
 # is_uv_tool_install
 # ---------------------------------------------------------------------------