Add scroll to models panel (max-height 400px, overflow-y-auto)

Frontend: accept legacy available-models response (groq_models / hf_spaces_models) and merge into unified list

Keep both Groq + HF models, remove rate-limited Groq models, unify model selection UI without backend labels

Collect tick history, render tracks and show per-model report

Load models via backend env API instead of localhost

inital build