DUNGEONS-34: implement Webka local streaming app

Co-authored-by: multica-agent <github@multica.ai>

frontend/composables/useApiError.ts

@@ -0,0 +1,7 @@
+export function useApiError() {
+  const { t, te } = useI18n();
+  return (error: any) => {
+    const key = `errors.${error?.data?.error || error?.name || "server"}`;
+    return te(key) ? t(key) : t("errors.server");
+  };
+}