mqqr 1.0.0

• Initial CRAN release.
• mqq_regression() implements multivariate Quantile-on-Quantile regression (Sinha et al. 2023) extending the bivariate QQR of Sim and Zhou (2015) with exogenous moderators, optional x * Z interactions, paired-bootstrap standard errors and Koenker–Machado pseudo R-squared.
• 3D surface, heatmap and contour visualisations (plot_mqq_3d, plot_mqq_heatmap, plot_mqq_contour, plot_mqq_interaction).
• MATLAB Parula colour scale as the default, alongside Jet, Turbo, BlueRed and the Sinha red-yellow-black palette.
• Helpers mqq_to_matrix(), mqq_export(), mqq_statistics().