Reproduction setup: SLURM scripts, configs

[dimanaStoyanova7]

• configs/ - 10 yaml config files for all model variants (Diffusion, PG-Diffusion, CoCoGen, PIDM-ME, PIDM-SE) for both Darcy flow and topology optimization
• slurm/ - SLURM job scripts for all training and eval jobs, including:
  • Fixed GPU detection (replaced exec/compile with sed + direct python call)
  • Added PYTHONPATH to resolve src/ module imports from temp scripts
  • Added CUDA availability check at job start
  • Configured for gpu-a100 and test-gpu partitions on DelftBlue