When all pages of a book are pruned, the Preview stage currently shows a raw JSON error: {"error":"ADT has no pages"}. There is no user-friendly feedback, and the Export stage is also broken in this state since there is nothing to export.
Expected behavior:
A clear empty-state screen should be shown when a book has no remaining pages after pruning
The screen should explain what happened and suggest next steps (e.g., go back to Extract and adjust the page pruning settings)
Export should either be disabled or show an equivalent message
Steps to reproduce:
Open a book where all pages have been pruned
Navigate to Preview or Export
I'll fix this — just filing so I don't forget.

When all pages of a book are pruned, the Preview stage currently shows a raw JSON error: {"error":"ADT has no pages"}. There is no user-friendly feedback, and the Export stage is also broken in this state since there is nothing to export.
Expected behavior:
A clear empty-state screen should be shown when a book has no remaining pages after pruning
The screen should explain what happened and suggest next steps (e.g., go back to Extract and adjust the page pruning settings)
Export should either be disabled or show an equivalent message
Steps to reproduce:
Open a book where all pages have been pruned
Navigate to Preview or Export
I'll fix this — just filing so I don't forget.