dev-container

Sets up and manages the isaaclab_arena Docker container — the single environment used for Arena's development, testing, training, and evaluation. Use when the user asks to set up the dev environment, bootstrap the project, get started on a fresh clone, start developing, build or rebuild the image, start or attach to the container, or run any command inside it. Also covers ./docker/run_docker.sh flag combinations (-r rebuild, -R rebuild without cache, -d/-m/-e custom dataset/model/eval mounts), docker exec usage, and the /isaac-sim/python.sh aliasing.