Refactor scheduled task repository and schemas for improved type hints and consistency

- Updated type hints from List/Optional to list/None for better readability and consistency across the codebase.
- Refactored import statements for better organization and clarity.
- Enhanced the ScheduledTaskBase schema to use modern type hints.
- Cleaned up unnecessary comments and whitespace in various files.
- Improved error handling and logging in task execution handlers.
- Updated test cases to reflect changes in type hints and ensure compatibility with the new structure.

check_tasks.py

@@ -7,15 +7,16 @@ from datetime import datetime
 from app.core.database import get_session_factory
 from app.repositories.scheduled_task import ScheduledTaskRepository
 
+
 async def check_tasks():
     session_factory = get_session_factory()
-    
+
     async with session_factory() as session:
         repo = ScheduledTaskRepository(session)
-        
+
         # Get all tasks
         all_tasks = await repo.get_all(limit=20)
-        
+
         print("All tasks in database:")
         print("=" * 80)
         for task in all_tasks:
@@ -32,14 +33,14 @@ async def check_tasks():
             print(f"Error: {task.error_message}")
             print(f"Parameters: {task.parameters}")
             print("-" * 40)
-        
+
         # Check specifically for pending tasks
         print(f"\nCurrent time: {datetime.utcnow()}")
         print("\nPending tasks:")
         from app.models.scheduled_task import TaskStatus
         pending_tasks = await repo.get_all(limit=10)
         pending_tasks = [t for t in pending_tasks if t.status == TaskStatus.PENDING and t.is_active]
-        
+
         if not pending_tasks:
             print("No pending tasks found")
         else:
@@ -48,4 +49,4 @@ async def check_tasks():
                 print(f"- {task.name} (ID: {task.id}): scheduled for {task.scheduled_at} (in {time_diff})")
 
 if __name__ == "__main__":
-    asyncio.run(check_tasks())
+    asyncio.run(check_tasks())