fix: Orientierungserkennung beim PDF-Upload statt erst bei OCR

Rotation wird jetzt in upload_pdf_get_info() erkannt, damit Thumbnails
bei der Seitenauswahl bereits richtig herum angezeigt werden.
Debug-Logging fuer _split_broad_columns hinzugefuegt.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

klausur-service/backend/cv_vocab_pipeline.py

@@ -2094,6 +2094,9 @@ def _split_broad_columns(
     """
     result: List[ColumnGeometry] = []
 
+    logger.info(f"SplitBroadCols: input {len(geometries)} cols: "
+                f"{[(g.index, g.x, g.width, g.word_count, round(g.width_ratio, 3)) for g in geometries]}")
+
     for geo in geometries:
         if geo.width_ratio <= _broad_threshold or len(geo.words) < 10:
             result.append(geo)

klausur-service/backend/vocab_worksheet_api.py

@@ -1172,10 +1172,25 @@ async def upload_pdf_get_info(
     session["pdf_page_count"] = page_count
     session["status"] = "pdf_uploaded"
 
+    # Detect orientation for each page so thumbnails are shown correctly
+    page_rotations: dict = {}
+    if OCR_PIPELINE_AVAILABLE:
+        for pg in range(page_count):
+            try:
+                img_bgr = render_pdf_high_res(content, pg, zoom=1.0)
+                _, rotation = detect_and_fix_orientation(img_bgr)
+                if rotation:
+                    page_rotations[pg] = rotation
+                    logger.info(f"Page {pg + 1}: orientation {rotation}°")
+            except Exception as e:
+                logger.warning(f"Orientation detection failed for page {pg + 1}: {e}")
+    session["page_rotations"] = page_rotations
+
     return {
         "session_id": session_id,
         "page_count": page_count,
         "filename": file.filename,
+        "page_rotations": page_rotations,
     }