refactor: restructure core→server, split large entity files into database module

- Move src/core/ → src/server/
- Split SerieList.py (531 lines) and series.py (414 lines) into src/server/database/
- Add database/models.py for SQLAlchemy models
- Update all test imports to reflect new structure
- Remove deprecated test files (test_serie_class.py, test_serie_folder_with_year.py)

src/server/exceptions/exceptions/Exceptions.py

@@ -0,0 +1,7 @@
+
+class NoKeyFoundException(Exception):
+    """Exception raised when an anime key cannot be found."""
+    pass
+class MatchNotFoundError(Exception):
+    """Exception raised when an anime key cannot be found."""
+    pass

src/server/exceptions/exceptions/__init__.py

@@ -0,0 +1,3 @@
+from src.server.exceptions.exceptions.Exceptions import MatchNotFoundError, NoKeyFoundException
+
+__all__ = ["MatchNotFoundError", "NoKeyFoundException"]