[Bug]: Exporting filtered split transactions filtered doesn't export any payee on the child transactions

### Verified issue does not already exist?

- [X] I have searched and found no existing issue

### What happened?

When exporting split transactions to a csv file, if a filter is added that only selects one of the child transactions, the payee field on that child transaction is blank in the csv file.

In this example, I have 3 transactions that have food as a category: 2 split transactions and 1 non-split transaction

I have added a filter for food so only transactions (2 children and 1 non-split transactions) are not greyed out

I then exported the current view but the csv file is missing payees on the 2 children transaction. The 1 non-split transaction is fine

I should also note that if no filter is added, the children transactions have payees.

A separate issue but connected to this. If the payee of a child transaction is changed to be different from the parent transaction, the export still uses the parent transaction for the child transaction.

In this example, the transaction for gas has a payee of "Costco Gas" but the exported file has a payee of "Costco"

### What error did you receive?

None

### Where are you hosting Actual?

Locally via Yarn

### What browsers are you seeing the problem on?

Firefox, Chrome, Microsoft Edge, Desktop App (Electron)

### Operating System

Windows 11

Reproduce the current-view CSV export with a filter selecting only a split child, then trace the CSV export entry point and the handling of child transaction payees. Verify both reported cases: filtered children retain their payees, and a child with a different payee exports that value rather than the parent’s. Add or update coverage for these export scenarios if the existing test location is found.

Scritto dal modello di indicizzazione a partire dal testo della issue.