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/statistics/pacf/Pacf.md

@@ -1,5 +1,7 @@
 # PACF: Partial Autocorrelation Function
 
+> *Strip away the intermediaries, and you'll see the true direct relationship.*
+
 | Property         | Value                            |
 | ---------------- | -------------------------------- |
 | **Category**     | Statistic                        |
@@ -16,8 +18,6 @@
 - Requires `period` bars of warmup before first valid output (IsHot = true).
 - Validated against mathematical properties and Durbin-Levinson recursion expectations.
 
-> "Strip away the intermediaries, and you'll see the true direct relationship."
-
 The Partial Autocorrelation Function (PACF) measures the correlation between a time series and its lagged values, after removing the effects of all intermediate lags. While ACF shows total correlation at each lag, PACF isolates the direct correlation, making it essential for AR model identification.
 
 ## Historical Context