StepUpload now has 3 phases:
1. File selection: drop zone / file picker → shows preview
2. Review: title input, category, file info → "Hochladen" button
3. Uploaded: shows session image → "Weiter" button
No more auto-advance after upload. User controls every step.
openSession() removed from onUploaded callback to prevent
step-reset race condition.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Phase 1 of the clean architecture refactor: Replaces the 751-line ocr-overlay
monolith with a modular pipeline. Each step gets its own component file.
Frontend: /ai/ocr-kombi route with 11 steps (Upload, Orientation, PageSplit,
Deskew, Dewarp, ContentCrop, OCR, Structure, GridBuild, GridReview, GroundTruth).
Session list supports document grouping for multi-page uploads.
Backend: New ocr_kombi/ module with multi-page PDF upload (splits PDF into N
sessions with shared document_group_id). DB migration adds document_group_id
and page_number columns.
Old /ai/ocr-overlay remains fully functional for A/B testing.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
