Classify panel membership and store it as label rules
classify_panel.RdRuns panel_describe() on df and adds two label rules keyed by entity:
panel_type (persistent/entrant/exit/transient/empty) and
panel_spell (seamless/segmented). Filter on them via, e.g.,
apply_sfw(df, sfw, panel_type = "persistent").
Usage
classify_panel(sfw, df, method = c("describe"))