style: apply ruff formatting to source and test files

tests/e2e/conftest.py

@@ -1,14 +1,14 @@
 # E2E test fixtures
 # Provides: full application state, end-to-end workflows, cleanup
 
-from typing import AsyncGenerator
+from collections.abc import AsyncGenerator
 
 import pytest
 from fastapi import FastAPI
 
 
 @pytest.fixture
-async def e2e_app() -> AsyncGenerator[FastAPI, None]:
+async def e2e_app() -> AsyncGenerator[FastAPI]:
     """Create full application instance for E2E testing."""
     from app.main import app_factory