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/reversals/sarext/Sarext.md

@@ -1,5 +1,7 @@
 # SAREXT: Parabolic SAR Extended
 
+> *The trend is your friend — but which way it accelerates depends on whether you're long or short.*
+
 | Property         | Value                            |
 | ---------------- | -------------------------------- |
 | **Category**     | Reversal                        |
@@ -17,8 +19,6 @@
 - Requires `2` bars of warmup before first valid output (IsHot = true).
 - Validated against TA-Lib reference implementation.
 
-> "The trend is your friend — but which way it accelerates depends on whether you're long or short." — QuanTAlib
-
 ## Introduction
 
 The Parabolic SAR Extended (SAREXT) is an enhanced version of Wilder's Parabolic Stop And Reverse that allows **separate acceleration factor configurations for long and short positions**. While standard PSAR uses the same AF start, increment, and maximum for both trend directions, SAREXT provides six independent AF parameters (three for long, three for short), plus a `startValue` to force initial direction and `offsetOnReverse` to add a gap buffer when the indicator reverses.