fix: task 1.5 poster check + fix stuck tests

- Fix structlog format string in folder_scan_service (%(key)d -> kwargs)
- Add nfo_download_poster setting check before poster download
- Create missing NFO fixture files (tvshow.nfo.bad/good) for repair tests
- Fix test_context_used_in_logging to check all call args not format string
- Fix test_system_settings_integration isolation via reset_all_scans

tests/unit/test_core_error_handler.py

@@ -263,8 +263,9 @@ class TestWithErrorRecoveryDecorator:
             fail_once()
             # Should have logged a warning with context
             mock_logger.warning.assert_called()
-            logged_msg = mock_logger.warning.call_args[0][0]
-            assert "my_context" in logged_msg
+            # context is a %s arg, so check all positional call args
+            logged_args = mock_logger.warning.call_args[0]
+            assert any("my_context" in str(arg) for arg in logged_args)
 
     def test_retryable_error_is_retried(self):
         """RetryableError (standard Exception subclass) is retried."""

tests/unit/test_system_settings_service.py

@@ -10,8 +10,12 @@ async def test_system_settings_integration():
     """Test SystemSettings service with actual database operations."""
     # Initialize database
     await init_db()
-    
-    # Test get_or_create (should create on first call)
+
+    # Reset all flags to a known-clean state before the test
+    async with get_db_session() as db:
+        await SystemSettingsService.reset_all_scans(db)
+
+    # Test get_or_create (should return record with all flags False after reset)
     async with get_db_session() as db:
         settings = await SystemSettingsService.get_or_create(db)
         assert settings is not None