Changes in version 0.5.0 - Initial CRAN submission. Features - Bifactor ESEM (B-ESEM), standard ESEM, and CFA for continuous and ordered-categorical data. - Continuous models via 'lavaan' native efa() blocks (MLR). - Ordered-categorical ESEM via 'lavaan' WLSMV; ordered B-ESEM via a custom diagonally weighted least squares (DWLS) path with polychoric correlations from 'psych', rotation-delta standard errors via 'numDeriv', and mean-and-variance-adjusted chi-square. - Target, geomin, and oblimin rotations via 'GPArotation'; the bifactor ESEM approach follows Morin, Arens and Marsh (2016). - Multi-group measurement invariance (configural through strict, with partial invariance), ESEM-within-CFA conversion, McDonald's omega reliability suite, and the Mehrvarz and Rouder (2026) alignment-ratio check for ICM-CFA misspecification. - Optional side-by-side comparison with Mplus output via 'MplusAutomation'.