CodeRabbit on #3943: Extract Pages copies the fields of the pages it takes, and
write_new (Combine, Extract, Split, Create) wrote that copy without the writable()
boundary saves use, so the new file kept a typed Password value. write_unchecked, which
write_new and Split's size measuring both go through, now writes the sanitized copy. The
other write_full/write_incremental calls in the engine build in-memory bytes (display,
previews, the working copy, print rasters), not files.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
