The reset useEffects in StepOrientation/Deskew/Dewarp/Crop were clearing
orientationResult when sessionId changed (e.g. during handleOrientationComplete),
causing the right side of ImageCompareView to show nothing. Using key={sessionId}
on the step components instead forces React to remount with fresh state when
switching sessions, without interfering with the upload/orientation flow.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Step components (Deskew, Dewarp, Crop, Orientation) had local state
guards that prevented reloading when sessionId changed via sub-session
tab clicks. Added useEffect reset hooks that clear all local state
when sessionId changes, allowing the component to properly reload
the new session's data.
Also renamed "Box N" to "Seite N" in BoxSessionTabs per user feedback.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Backend: merge gaps within 5% of image width — the spine area may have
thin ink strips splitting one physical gap into multiple detected gaps.
Only use gaps >= 2% width as split points.
Frontend: StepCrop now handles multi_page crop responses without
crashing on missing original_size/cropped_size fields.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>