Use cloud OCR for per-page content in cloud mode

When PAGEINDEX_API_KEY is set, index_long_document now fetches
per-page markdown via col.get_page_content() instead of running
local pymupdf. Cloud OCR produces cleaner output (preserves
tables, math, and section headers) than raw pymupdf text
extraction. Falls back to local pymupdf if the cloud call raises
or returns an empty result.

Author: rejojer

openkb/indexer.py

@@ -77,13 +77,28 @@ def index_long_document(pdf_path: Path, kb_dir: Path) -> IndexResult:
         "structure": structure,
     }
 
-    # Write wiki/sources/ — extract per-page content with pymupdf (not PageIndex)
+    # Write wiki/sources/ — per-page content
     sources_dir = kb_dir / "wiki" / "sources"
     sources_dir.mkdir(parents=True, exist_ok=True)
     images_dir = sources_dir / "images" / pdf_path.stem
 
     from openkb.images import convert_pdf_to_pages
-    all_pages = convert_pdf_to_pages(pdf_path, pdf_path.stem, images_dir)
+
+    all_pages: list = []
+    if pageindex_api_key:
+        # Cloud mode: fetch OCR'd markdown from PageIndex. get_page_content
+        # requires a page range, so pass "1-N".
+        from openkb.converter import get_pdf_page_count
+        page_count = get_pdf_page_count(pdf_path)
+        try:
+            all_pages = col.get_page_content(doc_id, f"1-{page_count}")
+        except Exception as exc:
+            logger.warning("Cloud get_page_content failed for %s: %s", pdf_path.name, exc)
+
+    if not all_pages:
+        if pageindex_api_key:
+            logger.warning("Cloud returned no pages for %s; falling back to local pymupdf", pdf_path.name)
+        all_pages = convert_pdf_to_pages(pdf_path, pdf_path.stem, images_dir)
 
     (sources_dir / f"{pdf_path.stem}.json").write_text(
         json_mod.dumps(all_pages, ensure_ascii=False, indent=2), encoding="utf-8",