feat: Add Pine Script implementation of SunnyBands indicator

pinescripts/Sunny_Bands.pine

@@ -0,0 +1,42 @@
+//@version=5
+indicator("Sunny Bands", shorttitle="SunnyB", overlay=true, format=format.price, precision=2)
+
+// Input parameters matching Python class
+length = input.int(50, "DMA Length", minval=1)
+atr_multiplier = input.float(1.5, "ATR Multiplier", minval=0.1, step=0.1)
+smooth_factor = input.int(2, "Smoothing Factor", minval=1)
+
+// Double EMA (DMA) calculation matching Python implementation
+ema1 = ta.ema(close, length)
+dma = ta.ema(ema1, smooth_factor)
+
+// ATR calculation equivalent to Python version
+atr = ta.atr(length)
+
+// Calculate bands
+upper_band = dma + (atr * atr_multiplier)
+lower_band = dma - (atr * atr_multiplier)
+
+// Signal detection using crossovers
+bullish = ta.crossover(close, lower_band)
+bearish = ta.crossunder(close, upper_band)
+
+// Plotting with similar colors to Python version
+plot(dma, "DMA", color=color.new(#009688, 0), linewidth=2)
+plot(upper_band, "Upper Band", color=color.new(#FF5252, 0), linewidth=2)
+plot(lower_band, "Lower Band", color=color.new(#4CAF50, 0), linewidth=2)
+
+// Signal markers
+plotshape(bullish, "Bullish Signal", style=shape.triangleup, 
+          location=location.belowbar, color=color.green, size=size.small)
+plotshape(bearish, "Bearish Signal", style=shape.triangledown, 
+          location=location.abovebar, color=color.red, size=size.small)
+
+// Background between bands like Python version
+fill(upper_band, lower_band, color.new(#673AB7, 90), title="Band Area")
+
+// Alerts equivalent to get_signals() method
+alertcondition(bullish, "Bullish Signal Detected", 
+              "Sunny Bands: Bullish crossover of lower band")
+alertcondition(bearish, "Bearish Signal Detected",
+              "Sunny Bands: Bearish crossunder of upper band")