Library manager docker image needed for production deployments

[xezpeleta]

Publish a library-manager Docker image to GitHub Container Registry, similar to the existing services:

• ghcr.io/lamb-project/lamb:latest
• ghcr.io/lamb-project/lamb-kb:latest
• ghcr.io/lamb-project/openwebui:latest

Suggested image name: ghcr.io/lamb-project/lamb-library-manager:latest

Required Changes

1. Modify .github/workflows/build-images.yml GitHub Action workflow to build and publish the library-manager image
2. Add the library-manager service to docker-compose.next.yaml with:
   • The published image reference
   • Required environment variables (LAMB_API_TOKEN, DATA_DIR, etc.)
   • Health check (already defined in docker-compose-example.yaml)
   • Service dependency in the lamb service

References

More info about Docker Next production deployment: #286

ping @juananpe