Restructure docling

[p-j-smith]

Following on from #38, restructure pyonb:

• make src/ocr/docling a uv package in packages/ocr/docling
• update docling Dockerfile to cache dependencies
• use DATA_FOLDER for mounting the docling and ocr-forwarding-api data volumes
• update docs on installing pyonb and running inference with docling
• tested locally, and test_inference_single_file_upload_docling and test_inference_on_folder_docling both pass

[Copilot]

Pull Request Overview

This PR restructures the docling package by moving it from a standalone service to a proper uv workspace package and improving the API integration. The changes simplify deployment while maintaining functionality for PDF-to-text conversion using docling.

• Restructured docling from src/ocr/docling to a proper uv package in packages/ocr/docling
• Updated API router to use async HTTP client and simplified environment handling
• Improved Docker configuration with dependency caching and updated volume mounting

Reviewed Changes

Copilot reviewed 11 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/ocr/docling/requirements.txt	Removed old requirements file as dependencies moved to pyproject.toml
src/ocr/docling/README.md	Removed old README in favor of new package documentation
src/ocr/docling/Dockerfile	Removed old Dockerfile replaced by new package-based version
src/api/app/routers/docling.py	Updated to use async HTTP client and simplified environment handling
pyproject.toml	Added docling optional dependency and workspace source configuration
packages/ocr/docling/src/pyonb_docling/api.py	Cleaned up import handling removing Docker-specific workarounds
packages/ocr/docling/pyproject.toml	New package configuration with proper dependencies
packages/ocr/docling/README.md	New documentation for using the restructured package
packages/ocr/docling/Dockerfile	New optimized Dockerfile with dependency caching
docker-compose.yml	Updated service configuration for new package structure
README.md	Updated installation instructions and project description

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[Copilot]

The COPY command copies './README' but the actual file is 'README.md'. This will cause the Docker build to fail.

Suggested change

	COPY ./README .
	COPY ./README.md .