Add metadata-driven BaJoR runtime options for contexts

[Tooyosi]

Move BaJoR job options into Context.metadata['batch'] and have Kade pass them through when creating training and prediction jobs.

What changed

• Added Batch::ContextRuntimeOptions to extract BaJoR facing runtime config from Context.metadata['batch']
• Updated training and prediction job submission services to use the shared context runtime options builder
• Extended Bajor::Client option serialization to include:
  • container_image_name
  • training_script_path
  • prediction_script_path
  • promote_script_path
  • pretrained_checkpoint_url
• Kept existing workflow_name, fixed_crop, and n_blocks behavior intact