- charts.py: candlestick (mplfinance, dark theme) with EMA20/50
overlay, Bollinger Bands, RSI subplot and 30/70 reference lines
- /signal now sends chart image with analysis as caption
- New /chart <PAIR> <TF> command for standalone chart view
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Multi-indicator signal engine with RSI, MACD, Bollinger Bands,
EMA trend filter, ADX strength gate, Stochastic, ATR, and
higher-timeframe trend confirmation. Twelve Data API client
with in-memory cache and rate limiting.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>