domain/ must be pure with no external dependencies. bbox.py imports
docling_core and belongs in infra/. Also refactor ServeConverter to
use the canonical to_topleft_list via BoundingBox instead of
duplicated manual coordinate conversion. Move docling-core to base
requirements since it is now needed in both modes.
Install torch and torchvision from the CPU-only index before docling
to avoid pulling CUDA/nvidia/triton dependencies. Update documentation
with measured image sizes (270MB remote, 1.9GB local).
Reflect the two Docker targets across README, getting-started,
contributing guides, and .env.example with new configuration
variables (CONVERSION_ENGINE, DOCLING_SERVE_URL, DOCLING_SERVE_API_KEY).
