feat(ocr): integrate spell-check post-processing for handwriting script types

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

ocr-service/main.py

@@ -22,6 +22,7 @@ from fastapi.responses import StreamingResponse
 from PIL import Image
 
 from confidence import apply_confidence_markers, get_threshold
+from spell_check import correct_text, load_spell_checker
 from engines import kraken as kraken_engine
 from engines import surya as surya_engine
 from models import OcrBlock, OcrRequest
@@ -39,6 +40,8 @@ ALLOWED_PDF_HOSTS = set(
     h.strip() for h in os.getenv("ALLOWED_PDF_HOSTS", "minio,localhost,127.0.0.1").split(",")
 )
 
+_SPELL_CHECK_SCRIPT_TYPES = {"HANDWRITING_KURRENT", "HANDWRITING_LATIN"}
+
 
 def _validate_url(url: str) -> None:
     """Validate that the PDF URL points to an allowed host (SSRF protection)."""
@@ -55,6 +58,7 @@ async def lifespan(app: FastAPI):
 
     logger.info("Loading Kraken model at startup (Surya loads lazily on first OCR request)...")
     kraken_engine.load_models()
+    load_spell_checker()
     _models_ready = True
     logger.info("Startup complete — ready to accept requests")
 
@@ -109,6 +113,8 @@ async def run_ocr(request: OcrRequest):
         if block.get("words"):
             block["text"] = apply_confidence_markers(block["words"], threshold)
         block.pop("words", None)
+        if script_type in _SPELL_CHECK_SCRIPT_TYPES:
+            block["text"] = correct_text(block["text"])
 
     return [OcrBlock(**b) for b in blocks]
 
@@ -170,6 +176,8 @@ async def run_ocr_stream(request: OcrRequest):
                             engine.extract_region_text, image,
                             region.x, region.y, region.width, region.height,
                         )
+                        if script_type in _SPELL_CHECK_SCRIPT_TYPES:
+                            text = correct_text(text)
                         blocks.append({
                             "pageNumber": page_idx,
                             "x": region.x,
@@ -231,6 +239,8 @@ async def run_ocr_stream(request: OcrRequest):
                     if block.get("words"):
                         block["text"] = apply_confidence_markers(block["words"], threshold)
                     block.pop("words", None)
+                    if script_type in _SPELL_CHECK_SCRIPT_TYPES:
+                        block["text"] = correct_text(block["text"])
 
                 total_blocks += len(blocks)
                 yield json.dumps({