feat(scan): whiten receipt backgrounds and embed OCR in PDFs

agents/fedeo-device-agent/Dockerfile

@@ -13,6 +13,9 @@ FROM node:20-bookworm-slim AS runtime
 ENV NODE_ENV=production
 ENV FEDEO_WORK_DIR=/work
 ENV FEDEO_SCAN_POSTPROCESS=false
+ENV FEDEO_SCAN_BACKGROUND_CLEANUP=true
+ENV FEDEO_SCAN_OCR=true
+ENV FEDEO_SCAN_OCR_LANGUAGE=deu+eng
 ENV FEDEO_SCAN_POSTPROCESS_PROFILE=document
 ENV FEDEO_SCAN_POSTPROCESS_PYTHON=/opt/fedeo-device-agent/.venv-opencv/bin/python
 ENV FEDEO_SCAN_POSTPROCESS_STRICT=false
@@ -28,6 +31,9 @@ RUN apt-get update \
         python3-pip \
         python3-venv \
         sane-utils \
+        tesseract-ocr \
+        tesseract-ocr-deu \
+        tesseract-ocr-eng \
     && rm -rf /var/lib/apt/lists/*
 
 COPY requirements-opencv.txt ./