time_series_model / sum_model objects and component constructors: wn(), ar1(), rw(), pl(), flicker(), and matern().gmwm2() to fit stochastic models directly from wavelet variance, with new helpers for parameter layout, transformations, theoretical WV computation, and model printing/plotting.gmwmx2_new() as a generic GMWMX interface for arbitrary X and y (in addition to GNSS-specific workflows), including explicit paths for complete and incomplete series (gmwmx2_new_no_missing() / gmwmx2_new_with_missing()).generate() methods for single and composite models plus missingness support (markov_two_states() and related plotting methods).get_sigma_mat_rw(), get_mean_diagonal_super_diagonals_cov_mat_rw_cpp()) and integrated them through RcppExports.data_generation.Rmd, estimate_composite_stochastic_models.Rmd, and gmwmx2_new.Rmd.longmemo and pkgdown URL metadata updates).download_all_stations_ngl, download_estimated_velocities_ngl and download_station_ngl so that it exit gracefully if NGL server is not reachable.download_all_stations_ngl, download_estimated_velocities_ngl and download_station_ngl with new address of the NGL: https://geodesy.unr.edu and using httr2.first version