Two unrelated newer-toolchain breakages bundled because they hit on the
same CI run and have the same shape (newer Rust got stricter about
patterns we used):
1. clippy 1.95 added the manual_midpoint lint which fires on every
instance of (a + b) / 2.0 with a help suggesting f64::midpoint.
CI runs with -D warnings so it became a hard error. Twelve sites
were affected — three real call sites in src/ohlcv.rs (median_price),
src/indicators/donchian.rs (DonchianOutput.middle),
src/indicators/ease_of_movement.rs (mid), and
src/indicators/super_trend.rs (hl2); plus eight test-helper
Candle::new constructions across accelerator_oscillator,
atr_trailing_stop, chaikin_volatility, chandelier_exit,
chande_kroll_stop, choppiness_index, super_trend, true_range.
All twelve switched to f64::midpoint (stable since Rust 1.85,
our workspace MSRV).
2. usize::is_multiple_of is still unstable (rust-lang/rust#128101) and
only stabilizes in Rust 1.87, but the MSRV CI job uses 1.85. The
two call sites in bollinger.rs and sma.rs (added with the R7
periodic-reseed tests) switched back to i % 2 == 0.
kingchenc
d52ddeaccb