chore: prepare v1.1.0 release

Update version numbers across Rust, Python, and documentation files to 1.1.0. Enhance the .gitignore to include macOS dSYM files and plans directory. Introduce new dependencies in the Rust core library and update the README to reflect recent performance benchmarks and backtesting engine capabilities. Add new artifacts to the benchmarks manifest and improve documentation for the backtesting engine API.

crates/ferro_ta_core/src/volatility.rs

@@ -1,10 +1,15 @@
 //! Volatility indicators.
 
-/// Average True Range — Wilder smoothed (TA-Lib compatible).
+/// Compute the Average True Range (ATR), Wilder smoothed (TA-Lib compatible).
 ///
-/// Seeds ATR with SMA of TR[1..=timeperiod] (bar 0 is skipped, matching TA-Lib).
-/// First valid output is at index `timeperiod`; indices 0..timeperiod are NaN.
-/// TR is computed on-the-fly (no separate tr Vec allocation).
+/// ATR measures market volatility by smoothing the True Range with Wilder's
+/// method. Seeded with the SMA of `TR[1..=timeperiod]` (bar 0 is skipped,
+/// matching TA-Lib). Returns non-negative values; the first `timeperiod`
+/// indices are `NaN`.
+///
+/// # Arguments
+/// * `high` / `low` / `close` - OHLC price series (same length).
+/// * `timeperiod` - Smoothing period (typically 14).
 pub fn atr(high: &[f64], low: &[f64], close: &[f64], timeperiod: usize) -> Vec<f64> {
     let n = high.len();
     let mut result = vec![f64::NAN; n];
@@ -33,7 +38,14 @@ pub fn atr(high: &[f64], low: &[f64], close: &[f64], timeperiod: usize) -> Vec<f
     result
 }
 
-/// True Range — max(H-L, |H-Cprev|, |L-Cprev|).
+/// Compute the True Range for each bar.
+///
+/// `TR = max(H - L, |H - C_prev|, |L - C_prev|)`. For bar 0, TR is
+/// simply `H - L` (no previous close available). Returns non-negative
+/// values for every bar (no `NaN` warmup).
+///
+/// # Arguments
+/// * `high` / `low` / `close` - OHLC price series (same length).
 pub fn trange(high: &[f64], low: &[f64], close: &[f64]) -> Vec<f64> {
     let n = high.len();
     let mut result = vec![f64::NAN; n];