feat(dynamics): add PlusDI, MinusDI, PlusDM, MinusDM indicators

Complete thin Dx-composition wrapper indicators with full test coverage:

- PlusDi/MinusDi: Directional Indicator wrappers (DiPlus/DiMinus from Dx)
- PlusDm/MinusDm: Directional Movement wrappers (DmPlus/DmMinus from Dx)
- Individual validation tests per indicator directory (TALib, Skender, bounds)
- Combined unit tests (DiDm.Tests.cs) and validation tests (DiDm.Validation.Tests.cs)
- Quantower wrappers + tests for all 4 indicators
- PineScript v6 implementations with compensated RMA
- Normalized .md documentation for all indicators and categories
- 182 tests passing, 0 failures

lib/volatility/atrn/Atrn.md

@@ -1,5 +1,7 @@
 # ATRN: Average True Range Normalized
 
+> *Context is everything. A \$5 ATR means nothing until you know the \$5 ATR from last month was \$2.*
+
 | Property         | Value                            |
 | ---------------- | -------------------------------- |
 | **Category**     | Volatility                        |
@@ -16,8 +18,6 @@
 - Requires 1 bar of warmup before first valid output (IsHot = true).
 - Validated against TA-Lib, Skender, and Tulip reference implementations where available.
 
-> "Context is everything. A \$5 ATR means nothing until you know the \$5 ATR from last month was \$2."
-
 ATRN transforms the absolute ATR into a relative measure by normalizing it to a [0,1] scale using min-max scaling over a lookback window. This answers the question: "Is current volatility high or low *compared to recent history*?"
 
 While ATR tells you *how much* an asset moves, ATRN tells you *how unusual* that movement is relative to the asset's own recent behavior. A value near 1 means volatility is at its recent high; a value near 0 means volatility is at its recent low; 0.5 means volatility is average.