Implement Datalab-compatible API with async endpoints and deepseek OCR backend

- New endpoints: /api/v1/convert, /api/v1/extract, /api/v1/segment,
  /api/v1/ocr, /api/v1/table_rec, /api/v1/marker (deprecated),
  /api/v1/create-document, /api/v1/files/*, /api/v1/thumbnails
- Async submit-and-poll pattern matching Datalab API spec
- X-API-Key authentication via API_KEY env var
- Filesystem-based request store for multi-worker support
- OCR_BACKEND=deepseek mode: uses deepseek-ocr via ollama for OCR
  (prompt: <|grounding|>Free OCR.)
- build_options() now propagates output_format to parsed_opts
- Fixed docs page CSS curly brace conflict with .format()
- Renamed marker_endpoint_referece.md -> marker_endpoint_reference.md
- Containerfile: added poppler-utils, pandoc; 3 gunicorn workers
- gunicorn.conf: post_fork hook for background worker threads

Containerfile

@@ -10,7 +10,8 @@ FROM rocm/pytorch:rocm7.2.4_ubuntu24.04_py3.12_pytorch_release_2.9.1
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
         curl ca-certificates tini procps git gcc g++ zlib1g-dev libjpeg-dev \
-        libpango-1.0-0 libharfbuzz0b libpangoft2-1.0-0 && \
+        libpango-1.0-0 libharfbuzz0b libpangoft2-1.0-0 \
+        poppler-utils pandoc && \
     apt-get remove -y python3-blinker || true && \
     rm -rf /var/lib/apt/lists/*
 
@@ -38,34 +39,42 @@ RUN mkdir -p /app/marker/static/fonts && \
     chown marker:marker /app/marker/static/fonts/GoNotoCurrent-Regular.ttf
 
 # ---- final image ----
-COPY app.py          /app/
+COPY app.py           /app/
+COPY request_store.py /app/
+COPY deepseek_ocr.py  /app/
 COPY gunicorn.conf.py /app/
 COPY entrypoint.sh    /app/entrypoint.sh
 
 RUN chmod +x /app/entrypoint.sh
 
-ENV \
-    HOME=/app \
-    PYTHONUNBUFFERED=1 \
-    PYTHONDONTWRITEBYTECODE=1 \
-    MARKER_OUTPUT_DIR=/app/conversion_results \
-    UPLOAD_DIR=/app/uploads \
-    OLLAMA_HOST=http://localhost:11435 \
-    DEESEEK_OCR_MODEL=deepseek-ocr \
-    AMD_COMPUTE=true \
-    TORCH_DEVICE= \
-    MODEL_DTYPE=float32 \
-    PORT=8000 \
-    HOST=0.0.0.0 \
-    LLM_SERVICE=marker.services.openai.OpenAIService \
-    USE_LLM=false \
-    OPENAI_BASE_URL=http://localhost:11435/v1 \
-    OPENAI_MODEL= \
-    GUNICORN_WORKERS=1
+ENV HOME=/app
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1
+ENV MARKER_OUTPUT_DIR=/app/conversion_results
+ENV UPLOAD_DIR=/app/uploads
+ENV RESULTS_DIR=/app/conversion_results
+ENV SELF_URL=http://localhost:8001
+ENV OLLAMA_HOST=http://localhost:11435
+ENV DEESEEK_OCR_MODEL=deepseek-ocr
+ENV AMD_COMPUTE=true
+ENV TORCH_DEVICE=
+ENV MODEL_DTYPE=float32
+ENV PORT=8001
+ENV HOST=0.0.0.0
+ENV LLM_SERVICE=marker.services.openai.OpenAIService
+ENV USE_LLM=false
+ENV OPENAI_BASE_URL=http://localhost:11435/v1
+ENV OPENAI_MODEL=
+ENV OCR_BACKEND=marker
+ENV DEEPSEEK_OLLAMA_HOST=http://localhost:11434
+ENV DEEPSEEK_OCR_MODEL=deepseek-ocr:latest
+ENV DEEPSEEK_OCR_PROMPT="<|grounding|>Free OCR."
+ENV API_KEY=
+ENV GUNICORN_WORKERS=3
 
 USER marker
 
-EXPOSE 8000
+EXPOSE 8001
 
 ENTRYPOINT ["/app/entrypoint.sh"]
 CMD ["gunicorn", "-c", "gunicorn.conf.py", "app:app_instance"]