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/filters/baxterking/BaxterKing.md

@@ -1,5 +1,7 @@
 # BK: Baxter-King Band-Pass Filter
 
+> *The business cycle is whatever remains after you strip away the trend and the noise. Baxter and King figured out the stripping.*
+
 | Property         | Value                            |
 | ---------------- | -------------------------------- |
 | **Category**     | Filter                        |
@@ -16,8 +18,6 @@
 - Requires `2K+1` bars of warmup before first valid output (IsHot = true).
 - Validated against TA-Lib, Skender, and Tulip reference implementations where available.
 
-> "The business cycle is whatever remains after you strip away the trend and the noise. Baxter and King figured out the stripping."
-
 The **Baxter-King Band-Pass Filter** is a symmetric finite impulse response (FIR) filter that approximates the ideal spectral band-pass by truncating the infinite sinc-like impulse response at lag $K$ and normalizing the weights to sum to zero. It extracts cyclical components with periodicities between $p_L$ (low) and $p_H$ (high) bars, rejecting both the DC trend and high-frequency noise. Output oscillates around zero with a fixed delay of $K$ bars.
 
 ## Historical Context