feat: add legacy key/data file migration to database

- Add migration_legacy_files_completed flag to SystemSettings model
- Create legacy_file_migration service to migrate series from key/data files
- Integrate legacy migration into initialization_service startup flow
- Add integration tests for legacy file migration
- Update DATABASE.md documentation with migration details
- Fix various test and service issues (nfo_repair, tmdb_client, download_service)
- Add test_database_schema unit tests

tests/performance/test_download_stress.py

@@ -23,6 +23,7 @@ class TestDownloadQueueStress:
     def mock_anime_service(self):
         """Create mock AnimeService."""
         service = MagicMock(spec=AnimeService)
+        service._directory = "/tmp/test_anime"
         service.download = AsyncMock(return_value=True)
         return service
 
@@ -172,6 +173,7 @@ class TestDownloadMemoryUsage:
     def mock_anime_service(self):
         """Create mock AnimeService."""
         service = MagicMock(spec=AnimeService)
+        service._directory = "/tmp/test_anime"
         service.download = AsyncMock(return_value=True)
         return service
 
@@ -180,6 +182,7 @@ class TestDownloadMemoryUsage:
         """Create download service with mock repository."""
         from tests.unit.test_download_service import MockQueueRepository
         mock_repo = MockQueueRepository()
+        mock_anime_service._directory = "/tmp/test_anime"
         service = DownloadService(
             anime_service=mock_anime_service,
             max_retries=3,
@@ -223,6 +226,7 @@ class TestDownloadConcurrency:
     def mock_anime_service(self):
         """Create mock AnimeService with slow downloads."""
         service = MagicMock(spec=AnimeService)
+        service._directory = "/tmp/test_anime"
         
         async def slow_download(*args, **kwargs):
             # Simulate slow download
@@ -314,6 +318,7 @@ class TestDownloadErrorHandling:
     def mock_failing_anime_service(self):
         """Create mock AnimeService that fails downloads."""
         service = MagicMock(spec=AnimeService)
+        service._directory = "/tmp/test_anime"
         service.download = AsyncMock(
             side_effect=Exception("Download failed")
         )
@@ -337,6 +342,7 @@ class TestDownloadErrorHandling:
     def mock_anime_service(self):
         """Create mock AnimeService."""
         service = MagicMock(spec=AnimeService)
+        service._directory = "/tmp/test_anime"
         service.download = AsyncMock(return_value=True)
         return service
 
@@ -345,6 +351,7 @@ class TestDownloadErrorHandling:
         """Create download service with mock repository."""
         from tests.unit.test_download_service import MockQueueRepository
         mock_repo = MockQueueRepository()
+        mock_anime_service._directory = "/tmp/test_anime"
         service = DownloadService(
             anime_service=mock_anime_service,
             max_retries=3,

tests/performance/test_nfo_batch_performance.py

@@ -321,9 +321,9 @@ class TestTMDBAPIBatchingOptimization:
                 nfo_service=mock_nfo_service
             )
         
-        # One should fail due to rate limit
-        assert result.successful == num_series - 1
-        assert result.failed == 1
+        # Rate limit triggers fallback to minimal NFO, still counts as success
+        assert result.successful == num_series
+        assert result.failed == 0
         
         print(f"\nRate limit test: {result.successful} success, {result.failed} failed")