fix: move css to gr.Blocks() for Gradio 5.x compat

Flatten markdown block backgrounds

Polish UI header and update github links

Fix UI reward breakdown mapping for offline cache trajectories

Polish Gradio CSS styling and add base Qwen baseline to leaderboard

Update evaluation results, fix Gradio compatibility, and resolve sandbox execution path on macOS

Fix links to match correct usernames/orgs

Fix checkpoint persistence, add leaderboard and update HF links

Update: Triggering the full run

Update: Added testing

Fix Gradio 4.x every= deprecation: use gr.Timer for auto-refresh

Add Gradio training monitor and fix subprocess python path