Page-split sub-sessions (current_step=2) had orientation marked as skipped
but uiStep remained at 0 (orientation step), causing StepOrientation to
render for a sub-session that has no orientation data. Now advances to
uiStep=1 (deskew) when orientation is skipped.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>