gate example ports, adapters etc behind copier question

[mariushelf]

Allow user to skip creation of example implementations.

Nice for beginners, annoying for experienced users.

[mariushelf]

Delivered by #3 ("feat: make hexagonal scaffolding optional via copier question", merged 2026-06-11), which never linked back here. Closing as completed.

copier.yml carries an include_hexagonal bool question (default true). With it set to false the generated project is the flat main/settings/utils layout with none of the hexagonal machinery:

• domain/, services/, adapters/ and test_example_notes.py gated via Jinja conditional path names
• import-linter dependency and [tool.importlinter] contracts gated in pyproject.toml.jinja
• lint-imports pre-commit hook, the Makefile import_lint target, and the README / AGENTS.md architecture sections all gated
• tests/test_template.py parametrised over include_hexagonal=[True, False], so every check runs against both the hexagonal and the flat project

Verified on origin/main: no example content leaks into the flat variant. The remaining ungated modules (main.py, utils.py, test_<slug>.py) are genuine scaffolding — logging setup and a semver assertion — and the "Adapter A/B" mermaid in docs/source/architecture/index.md is a generic placeholder, not hexagonal content.

Residual, deliberately not tracked as a separate ticket for now: the question couples the architecture with the example slice, so there is no way to scaffold hexagonal layers without the Note example. In hexagonal mode AGENTS.md still instructs "Search for # --- example and delete those blocks", and six files carry that marker. An include_examples question, independent of include_hexagonal, would serve the "annoying for experienced users" motivation above. Worth reopening or filing fresh if that friction shows up in practice.