New MatisseObject S4 class wrapping a Seurat object with isoform-resolved layers: junction counts, PSI matrix, inclusion/exclusion counts, event and junction annotation tables, and per-cell isoform metadata.
CreateMatisseObject(): primary constructor with input validation and automatic cell-barcode alignment.
CalculatePSI(): computes PSI matrices from junction count data and splice event definitions. Supports both MatisseObject and bare matrix input.