[codex] Harden Django template architecture

[JscorpTech]

Summary

• Make the default cookiecutter render minimal by turning optional integrations off unless selected.
• Add generated-project architecture guidance, stronger repo hygiene, pre-commit, Makefile quality targets, and CI template validation.
• Harden security defaults for allowed hosts, CORS, production secure settings, and debug-only static/media serving.
• Move account/auth sample flows toward service-layer boundaries and strengthen behavior/failure-path tests.

Validation

• python scripts/validate_template.py
• Rendered default project: isort --check-only --diff .
• Rendered default project: black --check .
• Rendered default project: flake8 .
• Rendered default project: python -m compileall
• Rendered default and all-optional projects: docker compose config

Notes

Full generated-project pytest and pyright were not run in Docker during this pass; the new quality gates and template render smoke checks are in place for CI.