Implemented fixtures & Implementing Resource pattern

api/app/transaction/models.py

@@ -96,7 +96,7 @@ class TransactionUpdate(TransactionWrite):
 
 class Split(SplitBaseId, table=True):
     transaction: Transaction = Relationship(back_populates="splits")
-    account: Account | None = Relationship()
+    account: Account | None = Relationship(back_populates="transaction_splits")
     payee: Payee | None = Relationship()
 
     @classmethod