fix: handle empty series name in data file sync

- Use folder name as fallback when series name is empty
- Skip series with both empty name and folder
- Add try/catch for individual series to prevent one failure
  from stopping the entire sync

src/server/services/anime_service.py

@@ -418,7 +418,26 @@ async def sync_series_from_data_files(
                 skip_load=True
             )
             added_count = 0
+            skipped_count = 0
             for serie in all_series:
+                # Handle series with empty name - use folder as fallback
+                if not serie.name or not serie.name.strip():
+                    if serie.folder and serie.folder.strip():
+                        serie.name = serie.folder.strip()
+                        log.debug(
+                            "Using folder as name fallback",
+                            key=serie.key,
+                            folder=serie.folder
+                        )
+                    else:
+                        log.warning(
+                            "Skipping series with empty name and folder",
+                            key=serie.key
+                        )
+                        skipped_count += 1
+                        continue
+
+                try:
                     result = await serie_list.add_to_db(serie, db)
                     if result:
                         added_count += 1
@@ -427,6 +446,14 @@ async def sync_series_from_data_files(
                             name=serie.name,
                             key=serie.key
                         )
+                except Exception as e:
+                    log.warning(
+                        "Failed to add series to database",
+                        key=serie.key,
+                        name=serie.name,
+                        error=str(e)
+                    )
+                    skipped_count += 1
 
             log.info(
                 "Data file sync complete",