F1: add SMMA and TRIMA moving averages (core)

First step of the indicator-family expansion (see the F section of
todo-detailed.md). Family F1 — Simple & Weighted MAs — gains two
members alongside the existing Sma/Ema/Wma:

- Smma — Wilder's smoothed moving average (RMA): SMA-seeded, then the
  (prev*(n-1)+x)/n recurrence. The average underlying RSI and ATR.
- Trima — triangular moving average: two stacked SMAs (n1/n2 split by
  parity) that triangular-weight the window. Genuine stacking — the
  outer SMA consumes the inner SMA's output.

Both implement the full Indicator trait with reference-value, warmup,
reset, batch==streaming and non-finite-input tests, a runnable doctest,
and are re-exported from the crate root. 208 core tests + 30 doctests
pass; clippy and fmt clean.

crates/wickra-core/src/lib.rs

@@ -46,8 +46,8 @@ pub use error::{Error, Result};
 pub use indicators::{
     Adx, AdxOutput, Aroon, AroonOutput, Atr, AwesomeOscillator, BollingerBands, BollingerOutput,
     Cci, Dema, Donchian, DonchianOutput, Ema, Hma, Kama, Keltner, KeltnerOutput, MacdIndicator,
-    MacdOutput, Mfi, Obv, Psar, Roc, RollingVwap, Rsi, Sma, Stochastic, StochasticOutput, Tema,
-    Trix, Vwap, WilliamsR, Wma,
+    MacdOutput, Mfi, Obv, Psar, Roc, RollingVwap, Rsi, Sma, Smma, Stochastic, StochasticOutput,
+    Tema, Trima, Trix, Vwap, WilliamsR, Wma,
 };
 pub use ohlcv::{Candle, Tick};
 pub use traits::{BatchExt, Chain, Indicator};