fix(ocr): increase memory limit to 10GB, reduce render DPI to 200

Surya 0.17 models use ~5GB idle. At 300 DPI on a multi-page PDF,
page images + inference tensors push past the 6GB limit, causing
OOM kills during 'Detecting bboxes'. Increased to 10GB and reduced
render DPI to 200 (still sufficient for OCR, uses ~44% less memory).

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

docker-compose.yml

@@ -78,8 +78,8 @@ services:
       dockerfile: Dockerfile
     container_name: archive-ocr
     restart: unless-stopped
-    mem_limit: 6g
-    memswap_limit: 6g
+    mem_limit: 10g
+    memswap_limit: 10g
     volumes:
       - ocr_models:/app/models
     environment: