CI happy path: seed a PDF document with a transcription block as admin, then
as the READ_ALL "reader" open it — assert the "Transkription lesen" control,
the read text, a plain "Transkription" header, and the absence of the
Lesen/Bearbeiten tabs (panel cannot switch to edit).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
