Fix SSR hydration mismatch for dates

Created ClientDate component that renders dates client-only via
useEffect to prevent server/client locale mismatches. Server
renders with de-DE as default, client updates to user's locale.

Applied to route detail (version dates) and route list (updated dates).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/journal/app/components/ClientDate.tsx

@@ -0,0 +1,15 @@
+import { useState, useEffect } from "react";
+
+/**
+ * Renders a date only on the client to avoid SSR hydration mismatches.
+ * Server renders empty, client fills in with user's locale.
+ */
+export function ClientDate({ iso }: { iso: string }) {
+  const [formatted, setFormatted] = useState(new Date(iso).toLocaleDateString("en-US"));
+
+  useEffect(() => {
+    setFormatted(new Date(iso).toLocaleDateString());
+  }, [iso]);
+
+  return <time dateTime={iso}>{formatted}</time>;
+}