Add ability to transfer funds between cash accounts

Feature request Add ability to transfer funds between cash accounts. Area (pick one) Chosen area: Cash Accounts / Portfolio Management Why does this matter? Portfolios can have multiple cash accounts, and users can deposit or withdraw funds for record‑keeping. However, there is currently no way to transfer money between these cash accounts. This makes it difficult to accurately track movements between accounts without creating manual workarounds. What should it look like? An option to select "Transfer" between any two cash accounts within the same portfolio, similar to deposit and withdrawal entries but with both accounts linked.