feat: report indexing progress with page counts in status panel

backend/app/main.py

@@ -182,6 +182,9 @@ def create_app(
             model=current.model,
             last_indexed_at=current.last_indexed_at,
             errors=current.errors,
+            pages_processed=current.pages_processed,
+            pages_total=current.pages_total,
+            current_file=current.current_file,
         )
 
     @app.post("/api/reindex", response_model=ReindexResponse, status_code=202)