columns width changed for better alignment

refactor(bothub-proxy): extract cost_details from SSE chunks, deduplicate formatCost

fix(bothub-proxy): prevent crash on network errors and sent headers

Fix continue work after connection lost

Add cost details to request logging in bothub-proxy.js

feat(bothub-proxy): add completion tokens to cacheInfo logging

Update README and proxy with bothub-models integration

initial code of proxy