The account activity tab rendered split transaction children as flat,
ungrouped rows, unlike /transactions which collapses them into a
parent row with indented children when "Group split transactions" is
enabled. Wire the same EntriesHelper.group_split_entries logic into
the account activity feed (UI::Account::ActivityDate, the actual
render path since the ViewComponent refactor superseded the old
accounts/show/_activity partial), sourcing split parents via the same
single-query batched lookup pattern already used by
TransactionsController#index.
Also forward view_ctx through entries/_split_group so split children
render correctly regardless of which page renders the group.
Fixeswe-promise/sure#3227
Co-authored-by: Gerald <248542187+gfr-free@users.noreply.github.com>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
