template-engine-copier skill: initial import

Copier + Jinja template-repository design skill: reference architecture,
implementation workflow, validation checklist, and a full worked example
template (questionnaire, extensions, resolvers, wrapper-first .scripts).

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

example/.scripts/copier/lib/--index-api.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+. ./.scripts/copier/lib/answers/--index-api.sh
+. ./.scripts/copier/lib/-bootstrap-one.sh