ggerror 1.0.0

New stat_error() summarises raw observation-level data into error bounds. Accepts fun = "mean_se" (default), "mean_ci" (95% normal- theory CI, no Hmisc dep), or a custom function following ggplot2’s fun.data contract. Also available via geom_error(stat = "error").
New sign_aware = TRUE routes signed per-row values (typically residuals) into one-sided bars whose direction encodes the sign. Enables one-layer lm() residual plots.
aes(error_neg = NA, error_pos = ...) is now the canonical idiom for one-sided bars — the cap and stem on the NA side auto-suppress. Passing 0 still renders but emits a soft deprecation warning; silence with options(ggerror.silent_zero_warning = TRUE) or tune the detection threshold via options(ggerror.zero_threshold = ...).
New diagnostics: NA values in symmetric error now warn with row indices (class ggerror_warn_error_na); negative values without sign_aware abort with row indices and a migration suggestion (class ggerror_error_negative_error_aes).
New vignette lm-residuals covering stat_error() and sign_aware with an lm() residual-plot demo.

ggerror 0.4.0

ggerror now includes a complete aestetic support for one sided error bars.
Added fixed per-side styling parameters for error bars: colour_neg / colour_pos, fill_neg / fill_pos, linewidth_neg / linewidth_pos, linetype_neg / linetype_pos, alpha_neg / alpha_pos, and width_neg / width_pos.
Fixed bug from 0.2.0: When supplying one-sided error bars, the unused side’s width can be set to 0, default, for example geom_error(aes(error_neg = 0, error_pos = se), width_neg = 0).
Added a vignette("ggerror") covering symmetric, asymmetric, one-sided, and per-side styling workflows.

New error_neg / error_pos aesthetics for asymmetric error bars. The bar extends error_neg in the negative direction and error_pos in the positive direction along the non-categorical axis.
One-sided bars are supported by setting the unused side to 0 explicitly (e.g. aes(error_neg = 0, error_pos = se) for an upward-only bar).
The existing symmetric error aesthetic is unchanged. Combining error with either error_neg / error_pos, or providing only one of the asymmetric pair, raises an error.

Initial release. Provides geom_error() (plus geom_error_linerange(), geom_error_crossbar(), geom_error_pointrange()) wrapping ggplot2’s error geoms behind a single error aesthetic with automatic orientation inference.