Split a pooled ts_tna()-family model into one full model per source
series. Each element is rebuilt with the same network type and the
shared state alphabet (params = list(alphabet = ...)), so every
network has the same node set in the same order — directly comparable
with each other and with the pooled summary model. Each element is a
complete ts_tna netobject: it keeps its own series data, plots with
plot.ts_tna(), and works with compatible Nestimate verbs. Statistical
procedures still require enough independent sequences for their sampling
design; a one-series split is descriptive rather than bootstrap-ready.
Value
A named tsn_series_networks collection containing one ts_tna
object per series. Its print, summary, and data-frame methods return a tidy
one-row-per-series index; plot() draws the sole model or a model selected
with its series argument.

