test: Fix integration test isolation (#739)

- Fix integration test isolation to prevent random directories in
project root.

### Problem

Running integration tests created random-named directories (e.g.,
`41SJFVD7V6`, `KEIN9WBF32`) in the project root instead of using
temporary directories.

### Root cause

The main `tests/integration/conftest.py` was missing the
`prepare_test_env` fixture that sets `APIFY_LOCAL_STORAGE_DIR` to a
pytest-managed temporary directory. Without this, Crawlee's default
behavior creates randomly-named directories in the current working
directory.

### Changes

1. **Added `prepare_test_env` fixture** to
`tests/integration/conftest.py`
   - Sets `APIFY_LOCAL_STORAGE_DIR` to `tmp_path`
   - Resets Actor and service locator global state between tests
   - Runs automatically via `_isolate_test_environment` (`autouse=True`)

2. **Removed duplicate** `tests/integration/apify_api/conftest.py`
   - Contained identical fixtures now provided by parent conftest
   - Tests inherit fixtures through pytest's conftest hierarchy

### Testing

After this fix, all storage directories are created under pytest's
temporary directory and automatically cleaned up after test runs.

---

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Author: vdusek

tests/integration/apify_api/conftest.py

@@ -1,10 +1,20 @@
 from __future__ import annotations
 
 import os
+from typing import TYPE_CHECKING
 
 import pytest
 
 from apify_client import ApifyClientAsync
+from apify_shared.consts import ApifyEnvVars
+from crawlee import service_locator
+
+import apify._actor
+from apify.storage_clients._apify._alias_resolving import AliasResolver
+
+if TYPE_CHECKING:
+    from collections.abc import Callable
+    from pathlib import Path
 
 _TOKEN_ENV_VAR = 'APIFY_TEST_USER_API_TOKEN'
 _API_URL_ENV_VAR = 'APIFY_INTEGRATION_TESTS_API_URL'
@@ -26,3 +36,56 @@ def apify_client_async(apify_token: str) -> ApifyClientAsync:
     api_url = os.getenv(_API_URL_ENV_VAR)
 
     return ApifyClientAsync(apify_token, api_url=api_url)
+
+
+@pytest.fixture
+def prepare_test_env(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> Callable[[], None]:
+    """Prepare the testing environment by resetting the global state before each test.
+
+    This fixture ensures that the global state of the package is reset to a known baseline before each test runs.
+    It also configures a temporary storage directory for test isolation.
+
+    Args:
+        monkeypatch: Test utility provided by pytest for patching.
+        tmp_path: A unique temporary directory path provided by pytest for test isolation.
+
+    Returns:
+        A callable that prepares the test environment.
+    """
+
+    def _prepare_test_env() -> None:
+        if hasattr(apify._actor.Actor, '__wrapped__'):
+            delattr(apify._actor.Actor, '__wrapped__')
+
+        apify._actor.Actor._is_initialized = False
+
+        # Set the environment variable for the local storage directory to the temporary path.
+        monkeypatch.setenv(ApifyEnvVars.LOCAL_STORAGE_DIR, str(tmp_path))
+
+        # Reset the services in the service locator.
+        service_locator._configuration = None
+        service_locator._event_manager = None
+        service_locator._storage_client = None
+        service_locator.storage_instance_manager.clear_cache()
+
+        # Reset the AliasResolver class state.
+        AliasResolver._alias_map = {}
+        AliasResolver._alias_init_lock = None
+
+        # Verify that the test environment was set up correctly.
+        assert os.environ.get(ApifyEnvVars.LOCAL_STORAGE_DIR) == str(tmp_path)
+
+    return _prepare_test_env
+
+
+@pytest.fixture(autouse=True)
+def _isolate_test_environment(prepare_test_env: Callable[[], None]) -> None:
+    """Isolate the testing environment by resetting global state before each test.
+
+    This fixture ensures that each test starts with a clean slate and that any modifications during the test
+    do not affect subsequent tests. It runs automatically for all tests.
+
+    Args:
+        prepare_test_env: Fixture to prepare the environment before each test.
+    """
+    prepare_test_env()