qt: Defer transaction signing until user clicks Send #33925

1. 
   151henry151 commented at 4:57 pm on November 22, 2025: contributor

   Fixes #30070

   When creating an unsigned PSBT from the GUI, the transaction was already signed during preparation, causing legacy inputs to have non-empty scriptSig fields. The PSBT parser then rejects them.

   This defers signing until the user clicks “Send” instead of signing during preparation. Fee calculation still works since transactions can be created without signing.

   Follows the approach suggested by @achow101 in the issue comments.

2. qt: Defer transaction signing until user clicks Send

   This fixes issue #30070 where creating unsigned PSBTs from the GUI
   would fail because the transaction was already signed during preparation,
   causing legacy inputs to have non-empty scriptSig fields.
   
   The fix defers signing until the user explicitly clicks 'Send', allowing
   truly unsigned PSBTs to be created while still supporting fee calculation.

   d95d440e10
3. DrahtBot added the label GUI on Nov 22, 2025
4. 
   DrahtBot commented at 4:57 pm on November 22, 2025: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/33925.

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5. 
   hebasto commented at 7:16 pm on November 22, 2025: member

   Please move this PR to the GUI repository: https://github.com/bitcoin-core/gui/pulls.
6. 151henry151 closed this on Nov 22, 2025

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151henry151 DrahtBot hebasto

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