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/obv/Obv.md

@@ -1,5 +1,7 @@
 # OBV: On Balance Volume
 
+> *Volume is the fuel that drives price.*
+
 | Property         | Value                            |
 | ---------------- | -------------------------------- |
 | **Category**     | Volume                        |
@@ -16,8 +18,6 @@
 - Requires `> 2` bars of warmup before first valid output (IsHot = true).
 - Validated against TA-Lib, Skender, and Tulip reference implementations where available.
 
-> "Volume is the fuel that drives price." — Joseph Granville
-
 On Balance Volume distills the relationship between price and volume into a single cumulative indicator. The premise is elegantly simple: volume flows into a security when it closes higher, and flows out when it closes lower. OBV tracks this flow as a running total, creating a momentum indicator that often leads price movements.
 
 Granville's insight was that volume precedes price. Institutional buying or selling shows up in volume before it manifests in price trends. When OBV rises while price remains flat, accumulation is occurring—a potential bullish signal. When OBV falls despite stable prices, distribution may be underway.