feat: update candlestick colors to black/white scheme

- Change bullish candles to white interior with black outline
- Change bearish candles to solid black
- Update all wick colors to black
- Enable borders for candlesticks

src/components/CandleChart.tsx

@@ -135,11 +135,12 @@ const CandleChart = forwardRef<CandleChartHandle, CandleChartProps>(
       });
 
       const candlestickSeries = chart.addCandlestickSeries({
-        upColor: '#10b981',
-        downColor: '#ef4444',
-        borderVisible: false,
-        wickUpColor: '#10b981',
-        wickDownColor: '#ef4444',
+        upColor: '#ffffff',
+        downColor: '#000000',
+        borderVisible: true,
+        wickUpColor: '#000000',
+        wickDownColor: '#000000',
+        borderUpColor: '#000000',
       });
 
       chartRef.current = chart;