Add Gemma 4 12B and Mistral 7B results

Add Gemma 4 E4B AutoMedBench Lite results

Keep leaderboard rows numeric with price source only

Add Gemma and Nemotron Lite results with per-task efficiency metrics

Add Nemotron 3.5 and GPT-OSS-20B results

Make theme toggle prominent

Add efficiency frontier plots page (cost/time/tokens/turns vs overall)