feat(07-07): localize lagoon validation with Laravel-shaped Polish messages

Replay of the user-api corpus needs lagoon::validate.* catalogs and
underscore-to-space attribute names so Go 422 bodies match Winter.

Co-authored-by: Cursor <cursoragent@cursor.com>

phrasebook/translator.go

@@ -88,6 +88,9 @@ func Activate[P interface{ ID() string }](app *backpack.App, plugins []P) error
 		return fmt.Errorf("phrasebook: app is nil")
 	}
 	cat := NewCatalog()
+	if err := cat.Load("lagoon", systemLangFS); err != nil {
+		return err
+	}
 	for _, p := range plugins {
 		hl, ok := any(p).(pact.HasLang)
 		if !ok {