feat: add admin/profile UI, i18n (fr/de/pt), fix CI pipelines

- Add admin panel link and profile modal in user menu dropdown
- Add French, German and Portuguese locale support (full translations)
- Register new locales across JS frontend and Rust backend
- Create CI pipeline (fmt, clippy, test, audit, build)
- Fix docker-build.yml (cache, real tests, reduced timeout)
- Fix docker-publish.yml (multi-arch via QEMU, latest tag, pre-publish tests)
- Add dependabot.yml for automated dependency updates

src/infrastructure/services/file_system_i18n_service.rs

@@ -139,7 +139,7 @@ impl I18nService for FileSystemI18nService {
     }
     
     async fn available_locales(&self) -> Vec<Locale> {
-        vec![Locale::English, Locale::Spanish]
+        vec![Locale::English, Locale::Spanish, Locale::French, Locale::German, Locale::Portuguese]
     }
     
     async fn is_supported(&self, locale: Locale) -> bool {