Refactor: bot pushes price data via API, drop yfinance from HF Space

Fix: use quantile_levels for Bolt predict, confidence from CI width

Fix: use ChronosBoltPipeline for Bolt models

Fix: flatten close prices, add debug logging for Chronos

Switch to chronos-bolt-tiny for HF free tier memory

Initial prediction engine — Chronos forecasts + FinBERT sentiment