v0.19.0

SeriesChart now draws with LayerChart instead of Lightweight Charts, and can show order price lines.

Adds

• levels prop on SeriesChart: labelled horizontal price lines (for example limit, stop, take profit, stop loss) with a tag at the right edge.
  • A level within 10% of the price range widens the scale to fit it; a farther one is pinned to the top or bottom edge with an arrow and its value.
  • Levels are announced to screen readers, and each tag names what it is, so colour is never the only signal.
  • Tags drop under the crosshair while inspecting and fade over the live price dot.
• Pure helpers in /chart and the root: levelsInRange, boundsWithLevels, levelPin, placeLevels, levelText, levelsSummary, stackLabels, xAtTime, candleMarks, candleWidthByStep, with their types and constants.

Changes

• The plot is drawn in SVG with layerchart 2.5.1 (pinned) and still loads lazily.
• Candles narrower than 3px draw as lines; a flat candle draws as a short horizontal line.
• With byTime, the x axis is a true time scale.
• If the plot fails to load, the empty text shows instead.
• Charts are 16px shorter: the attribution row is gone.

Breaking

• lightweight-charts is removed, along with the TradingView attribution.
• Removed exports: CHART_ATTRIBUTION_HEIGHT, TRADINGVIEW_NOTICE, TRADINGVIEW_CREDIT, TRADINGVIEW_URL, chartRows, ChartRow, chartSlots, slotAtTime, xAtSlot, colorWithAlpha, MAX_TIME_SLOTS.