exceptions adding in closed elements

src/warchron/model/model.py

@@ -159,6 +159,8 @@ class Model:
 
     def update_war(self, war_id: str, *, name: str, year: int) -> None:
         war = self.get_war(war_id)
+        if war.is_over:
+            raise ForbiddenOperation("Can't update a closed war.")
         war.set_name(name)
         war.set_year(year)