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/numerics/sigmoid/Sigmoid.md

@@ -1,5 +1,7 @@
 # SIGMOID: Logistic Function
 
+> *The sigmoid function is the S-curve that turns messy reality into neat probabilities—a mathematical diplomat that insists every answer must be between 0 and 1.*
+
 | Property         | Value                            |
 | ---------------- | -------------------------------- |
 | **Category**     | Numeric                        |
@@ -16,8 +18,6 @@
 - Requires `0` bars of warmup before first valid output (IsHot = true).
 - Validated against TA-Lib, Skender, and Tulip reference implementations where available.
 
-> "The sigmoid function is the S-curve that turns messy reality into neat probabilities—a mathematical diplomat that insists every answer must be between 0 and 1."
-
 The Sigmoid (Logistic) transformer maps any real-valued input to the bounded range (0, 1) using the standard logistic function. Its characteristic S-shaped curve makes it indispensable for probability estimation, neural network activations, and any scenario requiring bounded outputs from unbounded inputs.
 
 ## Mathematical Foundation