Add tests coverage for the transaction balancing with withdrawal

[carbolymer]

Context

makeTransactionBodyAutoBalance now returns TxBodyErrorBalanceNegative when the transaction balance is negative, instead of crashing with an Illegal Value in TxOut runtime error from toCompact on a negative Coin.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff
• Changelog fragment added in .changes/

[Copilot]

Pull request overview

Adds regression coverage around fee balancing for withdrawal-funded transactions, and hardens the experimental auto-balance path to avoid an unrecoverable ledger TxOut construction failure on negative balances.

Changes:

• Add two new calcMinFeeRecursive Hedgehog properties for withdrawal-funded balancing success/failure cases.
• Add generators for withdrawal-funded transactions (including a tiny-input variant).
• Add an early non-negative balance guard in makeTransactionBodyAutoBalance before constructing the initial change TxOut.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
cardano-api/test/cardano-api-test/Test/Cardano/Api/Experimental/Fee.hs	Adds new generators + properties to cover withdrawal-funded balancing scenarios.
cardano-api/src/Cardano/Api/Experimental/Tx/Internal/Fee.hs	Adds a pre-mkBasicTxOut balance check to avoid an irrecoverable crash on negative values.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

[palas]

It all looks correct and I've verified that:

• "withdrawal-funded transaction (output > input) succeeds" fails without withdrawal
• "underfunded transaction fails with TxBodyErrorBalanceNegative" fails without the patch in cardano-api/src/Cardano/Api/Experimental/Tx/Internal/Fee.hs

Maybe worth adding the new tests to the change-log too?