Add Starchannel indicator implementation and validation tests

- Implemented the Starchannel class, which calculates a volatility-based envelope using SMA as the middle line and ATR for band width.
- Added methods for updating the indicator with new data, batch calculations, and state management.
- Created comprehensive unit tests for the Starchannel indicator, validating various scenarios including manual calculations, consistency across modes, eventing, and handling of large datasets.
- Ensured that the indicator's outputs are finite and that band widths are consistent across different calculation modes.

docs/indicators.md

@@ -172,6 +172,7 @@ Price envelope and boundary indicators for breakout and mean-reversion strategie
 | [**PCHANNEL**](../lib/channels/pchannel/pchannel.md) | Price Channel | Highest high / lowest low; identical to Donchian |
 | [**REGCHANNEL**](../lib/channels/regchannel/regchannel.md) | Linear Regression Channel | Linear regression line with standard deviation bands |
 | [**SDCHANNEL**](../lib/channels/sdchannel/sdchannel.md) | Standard Deviation Channel | Moving average with standard deviation bands |
+| [**STARCHANNEL**](../lib/channels/starchannel/starchannel.md) | Stoller Average Range Channel | SMA with ATR bands; similar to Keltner but uses SMA |
 
 ### Statistics
 

docs/validation.md

@@ -251,7 +251,7 @@ No external reference exists. Implementation verified through unit tests, edge c
 | **Stochastic Momentum Index** | Smi | - | - | ✔️ | ❔ |
 | **Stochastic Oscillator** | Stoch | ✔️ | ✔️ | ✔️ | ❔ |
 | **Stochastic RSI** | Stochrsi | ✔️ | ✔️ | ✔️ | ❔ |
-| **Stoller Average Range Channel** | Starchannel | - | - | - | ❔ |
+| **Stoller Average Range Channel** | [Starchannel](../lib/channels/starchannel/starchannel.md) | - | - | - | ❔ |
 | **Super Trend Bands** | Stbands | - | - | - | - |
 | **SuperTrend** | [Super](../lib/trends/super/super.md) | - | - | ✔️ | ❔ |
 | **Swing High/Low Detection** | Swings | - | - | - | - |