A bunch more theme stuff

src-web/components/IsDev.tsx

@@ -0,0 +1,15 @@
+import type { ReactNode } from 'react';
+import { useAppInfo } from '../hooks/useAppInfo';
+
+interface Props {
+  children: ReactNode;
+}
+
+export function IsDev({ children }: Props) {
+  const appInfo = useAppInfo();
+  if (!appInfo?.isDev) {
+    return null;
+  }
+
+  return <>{children}</>;
+}