fix: skip_heal_gaps Parameter an Stream-Generator durchreichen

NameError behoben: skip_heal_gaps war nicht im Scope der
_word_batch_stream_generator Funktion.

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

klausur-service/backend/ocr_pipeline_api.py

@@ -1990,6 +1990,7 @@ async def detect_words(
             _word_batch_stream_generator(
                 session_id, cached, col_regions, row_geoms,
                 dewarped_bgr, engine, pronunciation, request,
+                skip_heal_gaps=skip_heal_gaps,
             ),
             media_type="text/event-stream",
             headers={
@@ -2100,6 +2101,7 @@ async def _word_batch_stream_generator(
     engine: str,
     pronunciation: str,
     request: Request,
+    skip_heal_gaps: bool = False,
 ):
     """SSE generator that runs batch OCR (parallel) then streams results.