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/ui/Ui.md

@@ -1,5 +1,7 @@
 # UI: Ulcer Index
 
+> *The ulcer-inducing anxiety of watching your portfolio decline—now quantified.*
+
 | Property         | Value                            |
 | ---------------- | -------------------------------- |
 | **Category**     | Volatility                        |
@@ -16,8 +18,6 @@
 - Requires `period` bars of warmup before first valid output (IsHot = true).
 - Validated against TA-Lib, Skender, and Tulip reference implementations where available.
 
-> "The ulcer-inducing anxiety of watching your portfolio decline—now quantified."
-
 Ulcer Index (UI) is a downside volatility measure that quantifies the depth and duration of drawdowns from recent highs. Developed by Peter G. Martin in 1987, UI captures what most volatility measures miss: the pain of being underwater. Unlike standard deviation or ATR that treat upside and downside moves equally, UI measures only the decline from peaks—the psychological stress that keeps investors awake at night.
 
 ## Historical Context