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/.copier/copier.yaml

@@ -0,0 +1,20 @@
+---
+_template_suffix: ".jinja"
+
+_exclude:
+  - ".git"
+  - ".copier"
+  - ".scripts"
+  - ".venv"
+  - "Taskfile.yml"
+  - "pyproject.toml"
+  - "copier-answers-new.yml"
+
+_jinja_extensions:
+  - copier_templates_extensions.TemplateExtensionLoader
+  - .copier/extensions/context_hook_extension/hook.py:ContextHookExtension
+  - .copier/extensions/resolvers/resolve_safe_identifier.py:SafeIdentifierExtension
+
+_answers_file: copier-answers.yml
+
+!include .copier/questionnaire/*.yml