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/answers/-new-ensure-existance.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+_copier_answers_new_ensure_existence() {
+  [ -f "${HL_V1_COPIER_FILE_COPIER_ANSWERS_NEW}" ] || touch "${HL_V1_COPIER_FILE_COPIER_ANSWERS_NEW}"
+}