Fix backend API parity: document filters, task days param, i18n locales, contract tests

- Add document list filter support (residence, type, category, contractor, is_active, expiring_soon, search) to handler/service/repo
- Add `days` query param parsing to ListTasks handler (matches ListTasksByResidence)
- Add `error.invalid_token` i18n key to all 9 non-English locale files
- Update contract test to include VerificationResponse mapping

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/i18n/translations/pt.json

@@ -7,6 +7,7 @@
   "error.email_already_taken": "Email ja em uso",
   "error.registration_failed": "Falha no registro",
   "error.not_authenticated": "Nao autenticado",
+  "error.invalid_token": "Token inválido",
   "error.failed_to_get_user": "Falha ao obter usuario",
   "error.failed_to_update_profile": "Falha ao atualizar perfil",
   "error.invalid_verification_code": "Codigo de verificacao invalido",