refactor: Simplify repository classes by inheriting from BaseRepository and removing redundant methods

app/repositories/credit_transaction.py

@@ -94,15 +94,15 @@ class CreditTransactionRepository(BaseRepository[CreditTransaction]):
             select(CreditTransaction)
             .where(CreditTransaction.success == True)  # noqa: E712
         )
-        
+
         if user_id is not None:
             stmt = stmt.where(CreditTransaction.user_id == user_id)
-            
+
         stmt = (
             stmt.order_by(CreditTransaction.created_at.desc())
             .limit(limit)
             .offset(offset)
         )
-        
+
         result = await self.session.exec(stmt)
-        return list(result.all())
+        return list(result.all())