xiacf 0.6.0

Directional Separation: xi_ccf() now explicitly separates causal directions (direction = "both", "x_leads", "y_leads") and returns Tidy data frames for easier downstream EDA.
Enhanced FWER Control: Excluded self-loops (autocorrelations) from the xi_matrix() Max-Statistic empirical null distribution, restoring statistical power for detecting true cross-edge pathways.
Lag 0 Synchronization: Included contemporaneous effects (Lag 0) in xi_matrix() C++ calculations to synchronize behavior with xi_ccf().
On-demand Thresholds: Updated extraction functions (extract_xi_acf(), extract_xi_ccf()) to dynamically recompute exact FWER thresholds using preserved raw data (data_raw).
Unified Plotting Aesthetics: Redesigned autoplot() methods for xi_ccf (vertical faceting) and xi_matrix (diagonal variable labels) to provide publication-ready, unified Tidyverse compatibility.
Bug Fixes: Fixed a C++ segmentation fault related to Lag 0 memory allocation, and resolved a Non-Standard Evaluation (NSE) bug in extractors that caused messy facet labels.
Test Suite Overhaul: Expanded and strictly validated the new tidy structures and directional logic (58 tests passing).

xiacf 0.5.0

FWER Control: Implemented strict Family-Wise Error Rate (‘FWER’) control via Max-statistic across all core functions (xi_acf, xi_ccf, xi_matrix).
Performance: Refactored core engines using C++ (RcppArmadillo) for MIAAFT and IAAFT surrogate generation, significantly improving computational speed.
Visualization: Enhanced autoplot methods to produce publication-ready ggplot2 charts utilizing base R expression() for native math rendering.
Compatibility: Improved backward compatibility to smoothly transition legacy sig_level = 0.95 (confidence level) inputs to significance levels, and systematically deprecated older functions with proper warnings.

Fixed a potential C++ RNG synchronization issue by delegating RNG state management entirely to Rcpp::RNGScope.