Add rules language support and improve password validation across the app

models.go

@@ -13,6 +13,7 @@ type Competition struct {
 	ID                 int64  `json:"id"`
 	Name               string `json:"name"`
 	AllowAnyScorerEdit bool   `json:"allow_any_scorer_edit"`
+	RulesLanguage      string `json:"rules_language"`
 	CreatedAt          string `json:"created_at"`
 	Role               string `json:"role,omitempty"`
 }