Calculate Herd Lying Concordance Metrics // Calculates Herd Lying Concordance (HLC) metrics from individual animal lying- behaviour data. HLC is a continuous framework for quantifying group-level behavioural cohesion from between-animal dispersion within observation intervals. The package implements standard deviation, mean absolute deviation, interquartile range, and entropy formulations, lying-weighted extensions, threshold- based synchrony comparisons, temporal summaries, and descriptive method-ranking tools. The HLC formulations are introduced in this package; related approaches to cattle behavioural synchrony include Raussi et al. (2011) doi:10.1017/S1751731110001928, Kok et al. (2023) doi:10.1016/j.applanim.2023.105906, and the activity metric framework of van Dixhoorn et al. (2024) doi:10.24072/pcjournal.489.