Unit Tests / test (push) Successful in 3s
## Summary Closes #1. - Adds real Django unit tests in `schasite/tests.py` (public pages, membership form + form validation, model helpers, calendar helpers, Stripe endpoints with mocks, auth/login_required behavior). - Includes the dockerize + Gitea Actions CI/CD base so PRs run tests and deploy only after Unit Tests succeed on a `master` push (company_site pattern). ## Test plan - [x] `DJANGO_ENV=dev DJANGO_SECRET_KEY=test-secret-key uv run python manage.py test schasite` — 30 tests OK - [ ] Open this PR and confirm Unit Tests / CI workflows run on the self-hosted runner - [ ] After merge to `master`, confirm Unit Tests run on push and deploy only proceeds when they pass Reviewed-on: #22