Codecov flagged 12 lines in crates/wickra-core/src/indicators/std_dev.rs
(file at 89.09%): const accessors period (64-66), value (68-71) and
Indicator-impl bodies warmup_period (110-112), name (118-120). None
of the existing tests inspected the metadata surface.
Add accessors_and_metadata asserting period == 14, warmup_period == 14,
name == "StdDev", and value() across both the None (pre-warmup) and
Some (post-warmup) branches.
std_dev.rs is now at 110/110 lines, no behavioural change.
kingchenc
73507b1cb6