feat: add Docker Compose environment to simulate SLURM for local testing

[mihow]

Context

Training jobs are submitted to HPC clusters via SLURM scripts in scripts/ and research/. There is no way to test these job scripts locally before scheduling real jobs, which makes iteration slow and wastes cluster resources on configuration errors.

Proposed Changes

Add a Docker Compose setup that simulates a minimal SLURM environment locally:

• review the DRAC / Compute Canada SLURM documentation to match their config as closely as possible: https://docs.alliancecan.ca/wiki/Running_jobs see the bash scripts in the research/ folder of this repo for real examples of how the pipeline in this repo is scheduled in DRAC's SLURM. For example: research/order_level_classifier/job_train_classifier.sh
• A container with a SLURM controller and single compute node (e.g., using giovtorres/slurm-docker-cluster or similar)
• The project mounted as a volume so job scripts can be submitted with sbatch
• GPU passthrough optional (for CPU-only smoke tests, training can run for 1-2 epochs)
• A README explaining how to start the environment, submit jobs, and check output
• Create a GitHub workflow to test SLURM jobs

This would allow developers to validate SLURM scripts, environment setup, and pipeline orchestration before submitting to the real cluster.

Related

• research/order_level_classifier/job_*.sh — existing SLURM job scripts
• scripts/train_species_classifier.sh — local equivalent (PR feat: add species classifier training pipeline #69)