v0.1.0: Full termchart clone - spark, line, candle, bar charts

- Sparklines with 8 tick levels and color
- Line charts with braille dots, Bresenham, Y-axis, legend
- Candlestick OHLC with green/red, wicks, bodies, doji
- Horizontal + vertical bars with 1/8th sub-cell precision
- Canvas + BrailleCanvas with optimized color output
- Color enum: 256-color, RGB hex, 9 named colors
- Zero dependencies, full termchart parity

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>