fix: computed fields missing in anniversary endpoints + missing account_id validation in installment update

api/app/routers/accounts.py

@@ -390,6 +390,11 @@ def update_installment(installment_id: int, data: DebtInstallmentUpdate, db: Ses
         installment = get_or_404(db, DebtInstallment, installment_id, "分期计划")
         update_data = data.model_dump(exclude_unset=True)
 
+        if "account_id" in update_data:
+            account = get_or_404(db, FinancialAccount, update_data["account_id"], "账户")
+            if account.account_type != "debt":
+                raise HTTPException(status_code=400, detail="分期计划只能关联欠款类型的账户")
+
         for field, value in update_data.items():
             setattr(installment, field, value)