Added page redirect after set show

frontend/src/pages/ShowsPage.tsx

@@ -1,4 +1,5 @@
-import { useEffect, useMemo, useState } from "react";
+import { useEffect, useMemo, useState, useRef } from "react";
+import { useNavigate } from "react-router-dom";
 
 type Show = {
     id: number;
@@ -12,6 +13,7 @@ type Show = {
 
 const GET_URL = "/api/v1/shows";
 const POST_URL = "/api/v1/current";
+const REDIRECT_DELAY_MS = 1200;
 
 const HHMM = /^(\d{1,2}):([0-5]\d)$/;
 
@@ -36,6 +38,8 @@ export default function ShowsPage() {
     const [loading, setLoading] = useState(true);
     const [posting, setPosting] = useState(false);
     const [error, setError] = useState<string | null>(null);
+    const navigate = useNavigate();
+    const redirectTid = useRef<number | null>(null);
 
     // フォーム状態
     const [selectedId, setSelectedId] = useState<number | null>(null);
@@ -82,6 +86,10 @@ export default function ShowsPage() {
 
     const current = useMemo(() => shows.find(s => s.id === selectedId) || null, [shows, selectedId]);
 
+    useEffect(() => {
+        return () => { if (redirectTid.current) window.clearTimeout(redirectTid.current); };
+    }, []);
+
     async function submit() {
         setError(null);
         if (!selectedId) { setError("エピソードを選択してください。"); return; }
@@ -107,6 +115,11 @@ export default function ShowsPage() {
                 body: JSON.stringify(payload),
             });
             if (!res.ok) throw new Error(`POST 失敗 (${res.status})`);
+            setError("設定しました。少々お待ちください…");
+            redirectTid.current = window.setTimeout(
+                () => navigate("/", { replace: true }),
+                REDIRECT_DELAY_MS
+            );
         } catch (e: any) {
             setError(e.message || "現在のエピソード設定に失敗しました。");
         } finally {