Duplicate child names get HA registry suffixes (_2); the template now
iterates the due sensors (which carry present/child_id/child_name as
attributes) and pairs counts by child_id, so suffixed duplicates are
listed and the household rollup is excluded by the presence guard.
Iterates present children from the Feature 10 presence sensors, lists
what each owes today from the remaining sensor, omits absent children
entirely. Blueprint inputs (time, notify service, send toggle); the
notify target is the household's choice, never hard-coded. PyYAML and
Jinja2 join the dev-only dependencies for blueprint template tests.