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/volume/vroc/Vroc.md

@@ -1,5 +1,7 @@
 # VROC: Volume Rate of Change
 
+> *Yesterday's volume is ancient history; what matters is how fast it's changing.*
+
 | Property         | Value                            |
 | ---------------- | -------------------------------- |
 | **Category**     | Volume                        |
@@ -16,8 +18,6 @@
 - Requires `> period + 1` bars of warmup before first valid output (IsHot = true).
 - Validated against TA-Lib, Skender, and Tulip reference implementations where available.
 
-> "Yesterday's volume is ancient history; what matters is how fast it's changing."
-
 VROC (Volume Rate of Change) measures the percentage or absolute change in volume over a specified lookback period. Unlike moving average-based volume indicators that smooth data, VROC provides a direct comparison between current volume and historical volume, making it particularly useful for detecting sudden volume surges or contractions that may signal significant market events.
 
 ## Historical Context