feat: MD 파일 병합 및 이미지 경로 통합 스크립트 추가 (#1)

- merge_markdown.py: 96개 페이지별 MD를 단일 파일로 병합
  - 이미지를 output/images/ 폴더로 통합, p{NN}_ prefix로 파일명 충돌 방지
  - file_range 파라미터로 부분 테스트 가능
- docs/tutorial.md: merge 명령어 및 사용법 문서화
- docs/history: 작업 이력 파일 추가

소요 시간: 10분 | Context: input 18k / output 2k tokens

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

debug_single_page.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python3
+"""
+Debug image extraction for a single page
+"""
+
+import os
+from pathlib import Path
+from marker.converters.pdf import PdfConverter
+from marker.models import create_model_dict
+from marker.output import text_from_rendered
+import pypdfium2 as pdfium
+
+
+def debug_single_page(pdf_path: str, page_num: int = 1):
+    """
+    Debug image extraction for a specific page (page_num is 1-indexed)
+    """
+    pdf_file = Path(pdf_path)
+    print(f"Debugging page {page_num} of: {pdf_file.name}")
+    print("=" * 60)
+
+    # First check what PyPDFium2 sees
+    print("\n1. Checking with PyPDFium2:")
+    try:
+        pdf = pdfium.PdfDocument(pdf_path)
+        page = pdf[page_num - 1]  # 0-indexed
+
+        print(f"   Page {page_num} objects:")
+        obj_count = 0
+        for obj in page.get_objects():
+            obj_count += 1
+            if hasattr(pdfium, 'FPDF_PAGEOBJ_IMAGE'):
+                if obj.type == pdfium.FPDF_PAGEOBJ_IMAGE:
+                    print(f"     - Image object found (old API)")
+            else:
+                print(f"     - Object type: {obj.type}")
+
+        print(f"   Total objects on page: {obj_count}")
+        pdf.close()
+    except Exception as e:
+        print(f"   PyPDFium2 error: {e}")
+
+    # Now check marker-pdf
+    print("\n2. Checking with marker-pdf:")
+    try:
+        converter = PdfConverter(
+            artifact_dict=create_model_dict(),
+        )
+
+        print("   Converting...")
+        rendered = converter(pdf_path)
+
+        # Check rendered object
+        print(f"\n   Rendered type: {type(rendered)}")
+
+        if hasattr(rendered, 'images'):
+            print(f"   rendered.images: {len(rendered.images) if rendered.images else 0} images")
+            if rendered.images:
+                for img_name, img_data in list(rendered.images.items())[:5]:
+                    print(f"     - {img_name}: {len(img_data) if img_data else 0} bytes")
+
+        # Extract using text_from_rendered
+        print("\n3. Extracting with text_from_rendered:")
+        text, metadata, images = text_from_rendered(rendered)
+
+        print(f"   Extracted images: {len(images) if images else 0}")
+        if images:
+            for img_name, img_data in images.items():
+                print(f"     - {img_name}: {len(img_data) if img_data else 0} bytes")
+                if not img_data or len(img_data) == 0:
+                    print(f"       ⚠️ WARNING: Empty image data!")
+
+        # Save a test image if available
+        if images:
+            output_dir = "output/debug_test"
+            os.makedirs(output_dir, exist_ok=True)
+
+            for img_name, img_data in images.items():
+                if img_data and len(img_data) > 0:
+                    img_path = os.path.join(output_dir, img_name)
+                    with open(img_path, "wb") as f:
+                        f.write(img_data)
+                    print(f"\n   ✓ Saved test image: {img_path}")
+                    break
+
+    except Exception as e:
+        print(f"   marker-pdf error: {e}")
+        import traceback
+        traceback.print_exc()
+
+
+if __name__ == "__main__":
+    import glob
+    pdf_files = glob.glob("input/*.pdf")
+    if pdf_files:
+        # Test page 2 (should have Figure 1.2, 1.3 according to the markdown)
+        debug_single_page(pdf_files[0], page_num=2)
+    else:
+        print("No PDF files found in input folder")