Page-split now creates independent sessions (no parent_session_id),
parent marked as status='split' and hidden from list. Navigation uses
useSearchParams for URL-based step tracking (browser back/forward works).
page.tsx reduced from 684 to 443 lines via usePipelineNavigation hook.
Box sub-sessions (column detection) remain unchanged.
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>
