add ruff format, ruff check, time_picker, project structure and imports reorganized

model/entity_metadata.py

@@ -2,7 +2,6 @@ from .descriptors import EntityDescriptor
 from ._singleton import Singleton
 
 
-class EntityMetadata(metaclass = Singleton):
-
+class EntityMetadata(metaclass=Singleton):
     def __init__(self):
         self.entity_descriptors: dict[str, EntityDescriptor] = {}