Extract the cookie parser, export-payload builder and fee-status helper
into their own modules and remove the filter/sort/load helpers the
database pushdown made dead, so the overview LiveView stays a thin
coordinator over focused units.
The View dropdown drives row density and whether the Member and Address
fields render as composite cells or split into their underlying columns;
the column manager toggles visibility and resets to the curated default.
All choices persist per browser through the URL/session/cookie/global
chain, so a saved layout survives reloads without a per-account store.
