Creating customers/suppliers no longer requires a default Customer/
Supplier Group or Territory on Kapital Bank Settings — when none is set,
the first leaf (non-group) node of the tree is used. A configured value
is still validated (must exist and be a leaf), with a clear message.
Also: the default-group / default-territory Link fields (and the
matching mapping child-table fields) now filter to is_group=0 so a group
node can't be selected.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>