sft+reward-fix: space/training/app.py

dashboard: synthesize PNGs on demand + cache-bust + pass --evidence_dir to vanilla

fix(deps): peft 0.18.0 -> 0.13.2 to match transformers 4.51.3

fix: switch trainer Space to vanilla GRPO path

fix: switch trainer Space to vanilla GRPO path

Update CERNenv Space