The Delete and View buttons are in the rulesList child template's each,
but their handlers are on the parent rulesMain and used
Template.currentData() — which returned the PARENT data context, not the
clicked rule. So the rule id was null: deleting failed with
'Match error: Expected string, got null', and 'View rule' always opened
the first rule. Add explicit data-rule-id to the buttons and read it in
the handlers so both operate on the rule actually clicked.