feat: rename to portuguese

AGENTS.md

@@ -82,3 +82,10 @@ For route/UI changes also start the app and verify `/health`, `/login`, the rota
 - For controls with white text, use the darker accessible red `--brand-deep` (`#C81018`), not the exact brand red. The exact brand red is used for borders, focus states, highlights, and other identity accents.
 - Keep branding usable on mobile and preserve visible keyboard focus states.
 - Default application name is `Contínuos CRR`; deployments can still override it with `APP_NAME`.
+
+## Language
+
+- Everything a member reads is European Portuguese: templates, flash messages, e-mail subjects and bodies, the seeded schedule names, and the `lang="pt-PT"` document attribute.
+- Weekday and month names, and every rendered date, come from `app/i18n.py`. Never use `calendar.month_name`, `date.strftime("%a"/"%b"/"%A"/"%B")` or `calendar.day_name` for user-facing text; the container locale is not Portuguese.
+- Stored enum values (`assignment.source`, `swap.status`, `notification_log.status`/`event_type`) stay English in the database and are translated for display by the Jinja filters registered in `app/main.py`.
+- Code, comments, tests names and `docs/` stay in English; only rendered strings are Portuguese.