feat(fiat-output): enable auto-completion for EUR transactions

[TaprootFreak]

Summary

• EUR fiat outputs are now included in the automatic completion flow via searchOutgoingBankTx()
• Uses valutaDate as fallback reference timestamp when isReadyDate is not set (which is intentional for EUR)
• Matches EUR fiat outputs to bank transactions via remittanceInfo just like non-EUR

Background

EUR fiat outputs were excluded from automatic completion because isReadyDate is intentionally not set for EUR in setReadyDate(). This meant manually executed EUR bank transfers were never automatically marked as complete.

Changes

• Extended query in searchOutgoingBankTx() to include EUR fiat outputs without isReadyDate but with valutaDate
• Added fallback to use valutaDate when isReadyDate is null for the timestamp comparison

Test plan

• Verify non-EUR fiat outputs still work as before (with isReadyDate)
• Verify EUR fiat outputs are now picked up by searchOutgoingBankTx()
• Verify matching via remittanceInfo works for manual Yapeal transfers
• Verify valutaDate comparison prevents false matches with old bank transactions