feat: Feinabstimmung mit 7 Schiebereglern fuer Deskew/Dewarp

Neues aufklappbares Panel unter Entzerrung mit individuellen Reglern:
- 3 Rotations-Regler (P1 Iterative, P2 Word-Alignment, P3 Textline)
- 4 Scherungs-Regler (A-D Methoden) mit Radio-Auswahl
- Kombinierte Vorschau und Ground-Truth-Speicherung
- Backend: POST /sessions/{id}/adjust-combined Endpoint

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

klausur-service/backend/ocr_pipeline_api.py

@@ -148,6 +148,11 @@ class ManualDewarpRequest(BaseModel):
     shear_degrees: float
 
 
+class CombinedAdjustRequest(BaseModel):
+    rotation_degrees: float = 0.0
+    shear_degrees: float = 0.0
+
+
 class DewarpGroundTruthRequest(BaseModel):
     is_correct: bool
     corrected_shear: Optional[float] = None
@@ -848,6 +853,93 @@ async def manual_dewarp(session_id: str, req: ManualDewarpRequest):
     }
 
 
+@router.post("/sessions/{session_id}/adjust-combined")
+async def adjust_combined(session_id: str, req: CombinedAdjustRequest):
+    """Apply rotation + shear combined to the original image.
+
+    Used by the fine-tuning sliders to preview arbitrary rotation/shear
+    combinations without re-running the full deskew/dewarp pipeline.
+    """
+    if session_id not in _cache:
+        await _load_session_to_cache(session_id)
+    cached = _get_cached(session_id)
+
+    img_bgr = cached.get("original_bgr")
+    if img_bgr is None:
+        raise HTTPException(status_code=400, detail="Original image not available")
+
+    rotation = max(-15.0, min(15.0, req.rotation_degrees))
+    shear_deg = max(-5.0, min(5.0, req.shear_degrees))
+
+    h, w = img_bgr.shape[:2]
+    result_bgr = img_bgr
+
+    # Step 1: Apply rotation
+    if abs(rotation) >= 0.001:
+        center = (w // 2, h // 2)
+        M = cv2.getRotationMatrix2D(center, rotation, 1.0)
+        result_bgr = cv2.warpAffine(result_bgr, M, (w, h),
+                                     flags=cv2.INTER_LINEAR,
+                                     borderMode=cv2.BORDER_REPLICATE)
+
+    # Step 2: Apply shear
+    if abs(shear_deg) >= 0.001:
+        result_bgr = dewarp_image_manual(result_bgr, shear_deg)
+
+    # Encode
+    success, png_buf = cv2.imencode(".png", result_bgr)
+    dewarped_png = png_buf.tobytes() if success else b""
+
+    # Binarize
+    binarized_png = None
+    try:
+        binarized = create_ocr_image(result_bgr)
+        success_bin, bin_buf = cv2.imencode(".png", binarized)
+        binarized_png = bin_buf.tobytes() if success_bin else None
+    except Exception:
+        pass
+
+    # Build combined result dicts
+    deskew_result = {
+        **(cached.get("deskew_result") or {}),
+        "angle_applied": round(rotation, 3),
+        "method_used": "manual_combined",
+    }
+    dewarp_result = {
+        **(cached.get("dewarp_result") or {}),
+        "method_used": "manual_combined",
+        "shear_degrees": round(shear_deg, 3),
+    }
+
+    # Update cache
+    cached["deskewed_bgr"] = result_bgr
+    cached["dewarped_bgr"] = result_bgr
+    cached["deskew_result"] = deskew_result
+    cached["dewarp_result"] = dewarp_result
+
+    # Persist to DB
+    db_update = {
+        "dewarped_png": dewarped_png,
+        "deskew_result": deskew_result,
+        "dewarp_result": dewarp_result,
+    }
+    if binarized_png:
+        db_update["binarized_png"] = binarized_png
+        db_update["deskewed_png"] = dewarped_png
+    await update_session_db(session_id, **db_update)
+
+    logger.info(f"OCR Pipeline: combined adjust session {session_id}: "
+                f"rotation={rotation:.3f} shear={shear_deg:.3f}")
+
+    return {
+        "session_id": session_id,
+        "rotation_degrees": round(rotation, 3),
+        "shear_degrees": round(shear_deg, 3),
+        "method_used": "manual_combined",
+        "dewarped_image_url": f"/api/v1/ocr-pipeline/sessions/{session_id}/image/dewarped",
+    }
+
+
 @router.post("/sessions/{session_id}/ground-truth/dewarp")
 async def save_dewarp_ground_truth(session_id: str, req: DewarpGroundTruthRequest):
     """Save ground truth feedback for the dewarp step."""