perf(ui): fewer Gradio steps + live STEPS_PER_EPISODE, tighter token cap

fix(api): Pydantic v2 step payload (exclude_none); env candidate_solutions; README Space API curl guide; Gradio API tab

Fix DPO Dataset Generation: Real preference pairs now exported from adversarial loop

Final Submission Upgrade: Advanced tier progression, professional README, and hackathon blog

Final cleanup for FORGE-v4: Colab entrypoint, OpenEnv API, 10x optimization, and Judge Narrative generation

Run app.py, generate logs/charts, and update guide.md