chore: remove frontend files

frontend/src/components/FeedList.tsx

@@ -1,45 +0,0 @@
-import React, { useEffect, useState } from "react";
-
-export default function FeedList() {
-  const [feeds, setFeeds] = useState<string[]>([]);
-  const [newUrl, setNewUrl] = useState("");
-
-  useEffect(() => {
-    fetch("/api/feeds")
-      .then((res) => res.json())
-      .then((data) => setFeeds(data));
-  }, []);
-
-  const addFeed = async () => {
-    if (!newUrl) return;
-    await fetch("/api/feeds", {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ feedUrl: newUrl }),
-    });
-    setNewUrl("");
-    const updated = await fetch("/api/feeds").then((res) => res.json());
-    setFeeds(updated);
-  };
-
-  return (
-    <div>
-      <h2>RSSフィード管理</h2>
-      <ul>
-        {feeds.map((url) => (
-          <li key={url}>{url}</li>
-        ))}
-      </ul>
-      <input
-        type="text"
-        placeholder="RSSフィードURLを入力"
-        value={newUrl}
-        onChange={(e) => setNewUrl(e.target.value)}
-        style={{ width: "300px" }}
-      />
-      <button onClick={addFeed} style={{ marginLeft: "8px" }}>
-        追加
-      </button>
-    </div>
-  );
-}