refactor: simplify NFO handling, remove legacy services

- Drop nfo_factory, nfo_repair_service, nfo_service, series_manager_service
- Delete key_resolution_service, consolidate into folder_rename_service
- Remove bulk of NFO-related tests (coverage via integration tests)
- Streamline SeriesApp, background_loader, initialization services
- Add folder_rename_service to scheduler

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/integration/test_concurrent_operations.py

@@ -55,43 +55,6 @@ class TestConcurrentDownloads:
         assert DownloadStatus.FAILED is not None
 
 
-class TestParallelNfoGeneration:
-    """Parallel NFO creation for multiple series."""
-
-    @pytest.mark.asyncio
-    @patch("src.core.services.series_manager_service.SerieList")
-    async def test_multiple_series_process_sequentially(self, mock_sl):
-        """process_nfo_for_series called for each serie in order."""
-        from src.core.services.series_manager_service import SeriesManagerService
-
-        manager = SeriesManagerService(
-            anime_directory="/anime",
-            tmdb_api_key=None,
-        )
-        # Without nfo_service, should be no-op
-        await manager.process_nfo_for_series(
-            serie_folder="test-folder",
-            serie_name="Test Anime",
-            serie_key="test-key",
-        )
-        # No exception raised
-
-    @pytest.mark.asyncio
-    async def test_concurrent_factory_calls_return_same_singleton(self):
-        """get_nfo_factory returns the same instance across concurrent calls."""
-        from src.core.services.nfo_factory import get_nfo_factory
-
-        results = []
-
-        async def get_factory():
-            results.append(get_nfo_factory())
-
-        tasks = [get_factory() for _ in range(5)]
-        await asyncio.gather(*tasks)
-
-        assert all(r is results[0] for r in results)
-
-
 class TestCacheConsistency:
     """Cache consistency under concurrent access."""