vaultless trade bug

[rouzwelt]

Motivation

Caution

This PR is chained after #1988

This PR adds a test for vautless trade (takeOrder4()),
this test currently fails most probably due to the fact that:

• recordVaultIO() for the order tries to first pushTokens() to the order owner for the order's input by calling increaseVaultBalance().
• This potentially can succeed fi orderbook has enough balance to cover for that token transfer, but if not, this direct token transfer fails due to the fact that the required tokens have not been taken from the taker yet
• Why this doesnt fail for taking normal orders? because there is no direct token transfer in increaseVaultBalance() and increaseVaultBalance(), its just a change in the vault balance mappings in that case

Solution

Checks

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• made this PR as small as possible
• unit-tested any new functionality
• linked any relevant issues or PRs
• included screenshots (if this involves a front-end change)

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✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch 2026-02-04-valtless-swap-bug

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