Add Step 4 fallback: generate key from folder name

- SerieScanner: generate key from folder when no key/data files exist
- Handle edge cases: non-Latin characters, special symbols in folder names
- anime_service: expose loading_status and loading_error fields
- Update tests to match new fallback behavior

src/core/SerieScanner.py

@@ -27,6 +27,7 @@ from src.core.providers.base_provider import Loader
 
 from src.server.database.connection import get_sync_session
 from src.server.database.service import AnimeSeriesService, EpisodeService
+from src.core.utils.key_utils import generate_key_from_folder
 
 logger = logging.getLogger(__name__)
 error_logger = logging.getLogger("error")
@@ -708,6 +709,31 @@ class SerieScanner:
                 )
                 return Serie.load_from_file(serie_file)
 
+        # Step 4: Generate key from folder name as last resort
+        # This handles edge cases like non-Latin characters or special symbols
+        try:
+            generated_key = generate_key_from_folder(folder_name)
+            year_from_folder = self._extract_year_from_folder_name(folder_name)
+            logger.info(
+                "Generated key for folder '%s' -> key='%s'",
+                folder_name,
+                generated_key
+            )
+            return Serie(
+                key=generated_key,
+                name="",  # Name will be fetched from provider if needed
+                site="aniworld.to",
+                folder=folder_name,
+                episodeDict=dict(),
+                year=year_from_folder
+            )
+        except Exception as exc:
+            logger.warning(
+                "Failed to generate key for folder '%s': %s",
+                folder_name,
+                exc
+            )
+
         return None
 
     def __get_episode_and_season(self, filename: str) -> tuple[int, int]: